You wouldn’t file a new FAFSA for the UCs, just add their codes to your current one. It is specific schools that ask you to verify. If a school feels its appropriate, it can change your FAFSA so then maybe other schools wouldn’t ask you to reverify.
In 2020, some schools gave out covid funds to any student who had a FAFSA on file even if they didn’t take a loan or get any federal money through the fAFSA filing. Something like that could happen again.