I think specifically for Sourcehut, to survive the DDoS they likely don't need 100% feature parity. Right now you can't even load their webpage - the service is effectively entirely down and users are left guessing what's going on. Getting web services back online would be significant.
The point for them would be to get breathing room to figure out a better long term plan. When the immediacy is gone, they'll be in a much better negotiating position with Cloudflare (or alternatives) for non-standard features.