I mean, hypothetically MS or Meta could already automatically do this...

I know you jest, but I think it wouldn't be a bad idea at all. There are languages whose grammar forces the speaker to explicitly clarify the source of information; Eastern Pomo, for example, has different verb forms for whether it's something you know first hand, saw, are repeating, or deducing. I imagine it's not only useful for the listener, it also helps the speaker realise if maybe they are building a shaky argument to make a point. I, for one, would be interested to see that system in English, it could lead to interesting developments.