Hi @joemanini,
It's possible to hide it - see here for a blog I wrote previously.
https://microsoft365pro.co.uk/2019/03/26/teams-can-you-do-private-chat-only/
This runs through a Teams tenant and takes a look at what can ultimately be hidden or disabled.
Just a point of caution that it may have an impact on other parts of the service. Would recommend that the ramifications are discussed with the customer and alternatives sought! Also taking into account the caveat that with Meetings even if you block it in the Desktop/Web Clients you can still access it via the phone app so you would need to block the Teams mobile app via Intune.
If anything, the blog shows there is no clean way to do this, or completely remove/disable it - the best is to to able to somewhat hide it. I would certainly try to deconstruct the reasons for why the customer would want to do this and see if there is a way to accommodate them first. It's a poor last resort as such and many would likely argue to look at alternate solutions rather than this.
Hope that answers your question!
Best, Chris
