But he was still a member of the Giants as of this morning. He wasn't signed to another team's 53-man roster, so the Giants released him. He actually requested to be released and the Giants honored his request.
Well, he's not the first to ask this. Aaron asked this from the Jets. The Jets didn't say no. The NFL League Office did.
https://www.barstoolsports.com/blog/3489672/caleb-williams-reportedly-wants-partial-ownership-of-whatever-nfl-team-drafts-him