I’m giving it exactly 2 weeks after implementation for most people to just suck it up and upload their IDs. I can’t think of a single “this new thing will break the service, people will mass quit!” thing every working out. Sure, some users left. But super majority, who has already built communities and are depended on it just keep churning.
Privacy and all that jazz aren’t that important to an average person. Everyone’s IDs are already circulating in a mix of Tinder, AirBnB, Twitter, <any random other app that just requires it>.