I am seeing very small ceiling "cracks" in three rooms.
I put cracks in quotation marks because they are not really cracks, more like a seam showing.... but I am not even sure my ceilings are drywall.
The house was built in 1955 and it is very hard to drive a nail anywhere and removal of one causes huge chips that don't look all that drywall-y to me.
There are heating cables in the ceilings- unused for decades but I mention them because you can kinda sorta see lengthwise indentations in some of my ceilings.
The new cracks do all run the same direction.

If I push on the areas adjacent to the cracks nothing moves and it looks like something that would be an easy fix with some spackle and a bit of paint. A pain to have to, sure, but doable.
My question is- is this abnormal and should I insist on the roofer covering the fix or is it par for the course and not a big deal?

I realize that photos are next to useless without scale but it is extraordinarily difficult to get a good shot.
They really are thin.

How many squares if roofing?

it is at least 12 and goes up from there depending on the pitch.

It is not uncommon for cracks to appear in walls and ceilings when removing multiple layers of roofing.

As noted above, you just pulled a LOT of weight off the structure.
Each layer is between 250 to 400 pounds per square, meaning you removed more than 6000 to 9600 pounds of weight from the roof.

All the rafters will rise slightly, and any ceiling joists carrying roof weight will also rise.
openings in the exterior weight bearing walls can also rise when the load is removed from their headers.

I have had 'pig' houses with 3 and even 4 layers of shingles that had all sorts of cracks appear as the weight bearing joists and walls moved after stripping the roof.

sdello- I get what you are saying and discussed that very thing with the roofers this morning.
I painted all of my ceilings with my own two hands when we moved in in '07 and feel certain that I would have noticed and repaired any cracks. I was painstaking in my preparation- I had a lot of time to kill and wanted things to be perfect, otherwise the husband would have done the painting :)

That said of course I am fallible and could be mistaken.
I think that I am mostly just wanting to know that it is not a sign of impending collapse and that I should just go quietly about my repairs and not think too much more about it.
I'm almost there :)

good luck with the repairs.