As an intern you should know that you're not privy to plans and should refrain from public speculation about future investment. Other people might confuse it with an official announcement which can land you in a lot of trouble.
Genuinely curious here: can you expand on this a bit? I'm not quite sure what you mean.
It's a serious fireable offence, or in this case a non offer at the end of the internship.
But you clarified it after the fact so minimized any damage.
Microsoft will likely not care about it, but it is the kind of thing to be mindful of.
Most of the big tech companies will have some kind of training explicitly calling out off the cuff comments and how to be mindful of them.