That distinction doesn't matter to Microsoft. Also it's funny how Google chat products once again go unmentioned... Their alternative is Chat (or idk, chat.google.com), and it's possibly even worse than Teams.
I think Google chat(s)'s issue may be lack of features and marketing, Microsoft Teams is drowning with bugs, performance issues, poor UI/UX design, etc.
I haven't used Teams enough to say, but Chat suffers from the latter things. UI keeps randomly changing in big ways, threading is confusing, there's serious lag just switching chats, takes forever to load, feature set is only on par with Slack circa 2015.
I bet most team members who switched from Slack to Microsoft Teams do not feel like they consented or were asked for their opinions beforehand.