Controlling chat with external consumer accounts, while still allowing meetings

The Teams admin centre has a switch for "People in my organization can communicate with Teams users whose accounts aren't managed by an organization".

I am expecting that if I disable this then my org users will no longer be able to chat with external consumer accounts like outlook, live, hotmail etc.

...but what is the implication for meetings? If I disable this setting and then try to invite a gmail or outlook consumer user to a scheduled Teams meeting... will that still work? I want to block the chat but not the scheduled meetings. 

Also, I assume this does not affect chatting with consumer users (eg. gmail) who are already added as guests in a team... ? Can anyone confirm on that point? Thanks!