Here is a list of officially compatible devices, though there are many other integrations that will work with community-developed apps and drivers:
https://docs.hubitat.com/index.php?title=List_of_Supported_Devices
Most (all?) ST branded devices I’m familiar with are zigbee and should work with hubitat just fine.
The only indication we have that the C7 hub even exists is from FCC filings. No announcements from hubitat, expected release date, etc. Personally I would not wait for this hub to be released if I were in the market for a Hubitat hub now.
