I feel like everyone who knew enough to know about Allo was also acutely aware that Google would probably kill it, and it would really suck to move friends to an app that’s just gonna join the graveyard with the dozen others
No, it came after Google Talk (XMPP) and was in fact based on the same protocol. The new thing it brought was live updates, so you could see other people typing, and it also had different types of content, not just text.