Seems like a pretty light innovation to me. I think a more important chat innovation is to know (for sure) if the person is actually online and working versus, online and not working, versus not online at all. Just noticing if the person is browsing the web versus on email is not enough information to know this. For example you can be on a word document creating your wedding invitations or for work. The app will have no clue. It needs to be an accurate record if the person is working or now. Then if you have that accurate record you can do a whole lot more with it as well (know exact times that you start and stop working).
The other potential chat innovation for business is having the teams configured ONE time by the company admin and then all team members are instantly in the correct teams and each person doesn't have to configure their teams.
Also better search of previous team discussions.
I'm guessing the business model will evolve :)