Yes, at some scale, if you put it in the jet of a black hole the radiation is going to destroy the image from physically blasting it off. That's not a reasonable concern to raise about film stability. Having your developed negatives x-rayed will not harm them, full stop.

The exception is that you shouldn't project slides for days and days on end, because the color couplers aren't as stable as grandpa's black and white negatives and do fade out eventually. Early color negative films had some problems too and would fade out over time regardless of radiation. But still, flying with a developed slide is not a problem, we are talking about the difference between a few mw of energy and sticking it right next to a 200W projector bulb.