So gpl is a licensor-licensee contract, if code and license is not shared to the user, then there is no contract to which the user is a party, rather the user is a beneficiary.

The offer of source code seems to be a way to facilitate the conveyance of source code through opt-in means separately from the object code rather than some legal trickery to create a user-licensee contract.

While the offer may indeed convey a licensee-user obligation, a compliant distribution would attach a license anyway, converting the user into a licensee and licensor to licensee in a recursive fashion

I wonder if lawyers specialize in this, it sounds very cool and not at all standard law, but somehow compatible with contract law

IANAL