see: https://9to5google.com/2018/12/02/google-hangouts-shutting-d...
“Allo will continue to work through March 2019 and until then, you’ll be able to export all of your existing conversation history from the app—here are instructions on how to do so.”
That’s not terrible, but the bar is very low for this kind of thing. It’s hardly seamless.
What does that even mean?
As far as I can tell, the whole difference between "Hangouts [Classic]" and "Hangouts Chat/Meet" is that the former was for consumers and the latter was for businesses/enterprises.
So they're shutting down the consumer version and moving all consumers to the business/enterprise version of the same product? That would just turn it back into what Hangouts was before they introduced Chat/Meet in the first place!
Chat and Meet replaced the classic interface for business. So, it's replacing classic for consumers, too.
(Which is interesting, because originally Hangouts was being announced to be pivoting to being business exclisive, with Hangouts classic for consumers left as-is with the implication that it, and consumer Hangouts as a thing, would eventually be killed, while Hangouts for business would be further developed, which is what Meet/Chat was. So it looks like Hangouts unpivoted.)