For anything over 250 devices, yes because the app and IDE can only display 250 devices regardless of capability in a single view like Things. When you add a new device you want to make sure to add it to a Room if you have over 250 devices.
The 100 device limit is per capability, eg. switch, motion, etc. and where it becomes a problem is when you want to add that new device to a SmartApp, like Alexa, and you can’t because there’s a limit of 100.