I disagree entirely, that’s simply incorrect. You can observe whether it is a cesspool or not whether you federate or not. The federation will not affect it at all. Everyone is able to go and use Threads, we won’t need to rely on “random screenshots or hearsay”, or to federate in order to see whether it’s good or not.
It’s an unknown quantity, 1000x bigger than the current fediverse. If we federate then block, there is just a mess to clean up. And you know the first few days are going to be a nightmare anyway, as they are with any social media platform, while the controls spin up and new ways to abuse them are found.
The benefit to doing it early is to let it land and let the smoke clear before making a judgement, without creating a mess for existing users. This is really obvious.