I don't get the point of this.
Since when did Sync masquerade itself as FOSS?
Just use whatever you want. Isn't that why we're all here?
Is the Sync noise getting to you? Just ignore it. It's natural since the app just opened up and there were a significant amount of Reddit refugees that badly wanted their app back.
I think it's par for the course for user traffic to normalize since the platform gets visitors just by simply existing.
But if they actually matched that against old users of the site, then it actually means something. Most of the users that left are usually power users and have used Reddit long enough to use third-party apps and can't stand the bullshit changes.
I actually got a notice like this several months ago even before YouTube did theirs.
If anything, Facebook's quite infamous for trying to combat and blockers in general. I remember back then when they obfuscated their web layout so much that it got tricky for some to filter or block sponsored or recommended content.