Disabling the device does nothing for your Zigbee (or Z-Wave, etc.) network--it just stops the driver code on the hub from running. The original intent of this feature was troubleshooting, but it also stops events from being generated, so it can be useful as a sort of "stop" for all automations triggered by the device. In your case, with physical removal, it probably wouldn't matter either way since it shouldn't be generating any in that state!
A similar question came up recently, and here was my response:
You can also read some other ideas there.
Honestly, with a Zigbee device, you'll probably be fine -- they find new routes on their own all the time (unless this happened to be a key route in your mesh--i.e., the only way back to the hub for some device due to range, etc.). The safest way would technically a polite removal. But it's nowhere near as picky as Z-Wave, IMHO.
EDIT: Now I see "battery" and realize this isn't a router/repeater node at all, so it should be even safer...
