You might want to rephrase that. SmartThings itself has a limit of 100 devices using the same capability. So you can only have 100 “switches” (which includes lightbulbs), or 100 sensors, etc. depending on the device “capability” being used, there will be a limit of no more than 100 Bluetooth devices connected to smartthings via BK.
For any given account, there may be less than 100 slots left in whatever device class BK’s going to use. (Just as an example, switches usually run out first.)