It should always be drywalled, taped, and primed, at a minimum. Minimum.

90% of houses have all painting done at the very end. I prefer working in a kitchen (if I’m the cabinet installer) that’s been primed because it’s cleaner- not getting drywall dust on me every time I brush past. It won’t affect the kitchen one way or the other once finished.

All my cabinets were installed on finished and primed walls for my new construction.

In my previous house the contractor who remodeled my kitchen finished, primed and painted the walls before he installed the cabinets. His theory was that if the cabinets were ever removed, it shouldn't look like an unfinished construction site.

I prefer contractors who don't take shortcuts.