From what others have reported it seems the web installer stops short of locking the bootloader leaving the user to do it as a separate manual job.
I guess you are translating this from FairphoneOS. The range of Android updates are described here What’s new in Android's May 2025 Google System Updates. That date relates to installed Google Play Services.
Do you not see an entry more close to “Vendor security patch level”?
It would be interesting if Fairphone do not quote Vendor SPL on their phones in light of the term not appearing in their release notes
and this question is asked Vendor Security Patch Level (SPL) in Fairphone 5 today.