Wondering if it will work with existing drivers.
I have ordered it. We will see what happens
I have an FP400 that I have paired with my Hubitat Hub via Matter. It was commissioned via my Aqara M3 Hub as a Matter over Thread device, and then shared via Matter to my Hubitat C8 Pro hub.
Main FP400 device - shows overall presence and illuminance using the "Generic Matter Motion/Light Sensor" driver which I manually assigned.
Child device automatically created for Zone 1 that I created using the Aqara mobile phone app.
I have only been testing this new sensor out. I have not tried pairing it to the Hubitat Hub via Zigbee.
Wish there was a way to create zones without the app.
OK, so it looks like it's working similarly to the FP2, in terms of having the zones come in as separate sensors. I guess the only difference then would be the Matter support...
Excellent!
If there are any capabilities missing that a different driver would be helpful for, let me know! I'm tempted to order one to test, though for $80 USD (and me not particularly needing yet another motion sensor and another iteration of these seeming to come out from different vendors every few months...), I'm not so sure.
Most of the "Generic Matter..." drivers should be generic enough to handle any device that matches the capabilities, regardless of which endpoints it exposes certain features on (which seems to be the main way many differ). It does look like there might be "occupancy" on two different endpoints, based on your screenshot, which should also be why the child device was created (also something these drivers do). In my testing with a Meross device that this feature was added for, I wasn't able to get a good description of what endpoint actually meant what (I think I was looking for the descriptor that specified what technology the occupancy feature used: PIR, mmWave, etc., but it was optional and they didn't specify or it used something generic enough that was the same for both -- I don't remember anymore, but my point is that maybe this one could be different and would require some looking into if that would be useful in the first place 
).
I also have one setup via my M3 using matter to connect to hubitat. As @ogiewon stated the motion zones pulled over and are functioning correctly. The only thing I see missing is the lux reporting does not appear as a device like the FP300 does. Also when the "zones" import from M3 they are identified as the generic name "Spatial Multi-Sensor FP400" rather than the name of the zone. If you have multiple zones configured they all come over with the same name. I got around this by deleting them and then adding them one at a time to the M3 then adding them to HE with configure command. Not sure if this can be addressed?
I definitely find the immense amount of configurability in the Aqara app impressive yet overwhelming. I'm finding it nice to eliminate the need for multiple sensors to create different automations in parts of the room pretty slick.
I read Zigbee has more details than matter on the Aqara app.
@ogiewon @halfrican.ak how does this sensor compare to other Aqara sensors you own? I have a FP2 and a FP300. The FP2 does a decent job in our bedroom but does have an occasional ghost or marks the room vacant when we are in there.
Good question. IMHO, the FP400 feels a lot like the FP2, but with Matter over Thread/Zigbee support instead of HomeKit. Since I am not using the FP400 in “production”, I cannot say how its performance compares to the FP2.
I have paired the FP400 to the Aqara M3 hub with both Zigbee and Matter over Thread. Unlike the FP300, really didn’t notice any significant differences in what settings are available in the Aqara mobile app. Maybe I just missed what the differences are? 
Using Matter over Thread (MoT), the FP400 is paired to my Apple Home/AqaraM3 Thread network. When the FP400 is shared via Matter to my C8 Pro hub, there is no dependency on the Aqara M3 hub. The only dependency is on the Thread Border Router (TBR).
Using Zigbee to pair the FP400 to the Aqara M3 hub, would require the M3 hub to act as a Matter Bridge in order to share the FP400 with the Hubitat Hub. I have not tried this configuration, so I am not sure if all of the FP400 Presence “Zones” would even come over correctly via the M3’s Matter Bridge functionality.
I really haven't had time to test mine long enough to 100% if there are ghosting or missed presence states. I have mine configured for zigbee to my M3 and then my M3 is paired via matter to my HE C8PRO.
In my early testing the FP400 is definitely more responsive than my FP300s but I imagine that could be partially due to it being powered from mains rather than battery so battery management isn't a factor.
So it looks like everyone above paired through a m3 hub. If paired with the hubitat hub directly over zigbee and it doesn't appear have a valid driver or atleast connect with one. It pairs with a generic zigbee device driver.
It should be easy nowadays to create an FP400 dedicated custom driver with the help of the AI...
I take my words back - this Zigbee device protocol is rather complicated... 
Lol. Yea. It is and aqara seem to like to use custom clusters for some stuff.
That said i have made progress. I have a nearly functional driver for basic functions. General occupancy and light sensor data seems to be recognized now. Not ready for anyone else to use but atleast getting close to functional. Looks like the count and maybe the zones can even be obtained to. Just not sure how zones would be setup from hubitat. I actually had to pull some info from one of your drivers to get the full list of endpoints and clusters avaliable.
If I were writing a Zigbee driver for the FP400, the FP400 Parent Driver would expose the Overall Motion status as well as the Illuminance. It would create a child motion device to represent each of the user-defined FP400 “Zones”.
Yea.. the problem is how do we define those areas on a Hubitat Hub. The general Occupancy and Illuminance i believe are working, I think i can see the endpoints for the zones, but how do we configure them.
Lots of info in this GitHub discussion regarding the FP400. Might be helpful to someone writing a Hubitat Zigbee driver.