There isn't a wall or ceiling anywhere that is fully plumb and level in all dimensions. Ceilings are especially problematic in that regard when using modern materials like drywall. Gapping is, unfortunately, normal. Even in new construction.

Caulk can fix a lot of sins with painted finishes. I would want a paintable caulk used, and then use the cabinet company's paint to touch it up.

Or, the alternative would have been to take care of the issue during the design phase. Because the issue is endemic to "to the ceiling" look, I always use a multipart molding when taking moldings to the ceiling. That allows a certain amount of "travel" to occur with the molding used at the top. The intermediate piece allows the crown to float up or down and be installed tight to the ceiling. Here's an example of the type of thing I'm talking about. This is exaggerated, because the customer didn't want to do stacked cabinets and has 12" of space between the top of the cabinets and ceiling. It wouldn't be my personal combination of moldings for the situation, but it's what she asked for.

Yes gaps like that are extremely typical.

Two approaches to fix:
Spackle or caulk and then paint (easiest)

Re-float and texture the ceiling again to level it at that spot.

I am surprised the painters did not just caulk it on their own.

Thank you for the replies. It's "reassuring" that it's a widespread and typical problem.

The painters are scheduled to come back, so we'll ensure they go with a paintable caulk.

Thanks again.