I just verified this -- the information is accurate. It's account wide, not on a per app basis. The exact text is: "You can still add 79 out of the maximum 1

I just verified this -- the information is accurate. It's account wide, not on a per app basis. The exact text is: "You can still add 79 out of the maximum 100 devices allocated for your team." I removed a device and the text remained -- 79 out of 100. I'll check again later to see if it's not a caching issue.