I can't see the requirement to share code with users on request anywhere in the GPLv3. It explicitly excludes interaction over a network in section 0:
"To “convey” a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a user through a computer network, with no transfer of a copy, is not conveying."
Are you sure you're not thinking of the Affero GPL?
with gpl v2, it was a requirement. hence gpl v2 licensed applications such as wordpress and drupal don't need to be shared with site users
code built upon the framework is derivation and thus, has to be licensed accordingly