Do you know what instance it was hosted on? The only one I’m seeing was created 11 hours ago with two videos, so I’m assuming that’s not it. It’s possible the instance went down. I’d say it’s possible it was defederated, but we’re on different instances, so it’d have to be a big whoopsie to have been removed by multiple instances.
I feel like logging in with Facebook and Google on sites is just as much about them gaining access to scrape more info about you as it is for your “convenience.” While there could be value with Lemmy, it’s not nearly what it is with Facebook and Google. So I would say not likely.