Does the people remember the comet incident?
I don't think there's ever been official confirmation that those characters appearing is anything more than a cameo, so it isn't even clear whether the meteor incident occurred in Weathering With You. (As I recall, there was never a clear view of the region of Japan where it happened to show whether or not there's a crater.)

That said, if they did occur in the same universe then people would have remembered it - it was a fairly major event that destroyed an entire town - but it could well be something that has already faded from most people's minds because it wasn't a cause of many deaths.


   Since, if Mizuha is living in Tokyo, then this must take place in the timeline where they managed to bring everyone to the school before the impact.