When and where will NPSP release notes be posted for Summer 25?

They don’t post release notes for bug fixes and resolving known issues.

Looking at the repository it appears that this release updates the API version on Relationship classes so organizations can enable the new ICU Locale.

They fixed this issue

They also fixed an address-related issue, but I’m not sure which Known Issue that maps to.

I think that’s about it that anyone would notice.