I think registration is open again, but it's developed by the same guy who made pixelfed, so it should have similar policies about privacy and security.
Loops seems to still be in development. Where is the best safe place currently to watch videos? YouTube besides tracking everything and ads has unblockable far right propaganda on recommendations. There is also a lot of censorship of content.
I haven't found any alt platform that has much content. Haven't ever tried TikTok though because of various privacy and ethical reasons.
There's another Tik tok alt for the Fediverse called Vidzy, I'm not entirely sure about their privacy and security things, but the devs seem pretty cool, it doesn't have a dedicated app though, only web ui.
I know loops is working towards being compatible with vidzy in the future tho.