The recent bill passed in Arizona, where e621 is hosted, has functionally made the site illegal unless it bends the knee and violates the privacy of millions of people. As such, there is a high risk that it will be going down, hopefully they'll be able to relocate and set back up within a few months, making the outage temporary, but in the worst case scenario, it will be gone for good.

I recommend you hope for the best and prepare for the worst, if you want to download all your favorites, I highly recommend using this tampermonkey script to add an option to download all of your favorites.

https://re621.app/

Stat safe y'all <3