I do not think it is disputed that the egyptian of old had slaves which were from the region. I think what is disputed is that the exodus narrative had any basis in reality. There is as far as i can tell no basis to "Egyptian enslaved whole folk", they used and captured folk in some war (as mentionned Hyksos above) they had slave trade, but it does not seem they went out of their way to target specifically a whole Ethnic group and enslave them. From what i could read, neither did they use slave as cheap stuff to whip and use to death.
So stating there were "hebrew" slave in egypt is beyond the point. The point is that it was nether systematic, nor it was in such massive numbers, nor the treatment is as people think it was.
As such , the imagery your uncle has is with a good certainty false, and its origin has only hollywood.
Mostly. While Egypt didn't have such a policy of moving whole ethnic groups around, like the Assyrians did, in the Hyksos instance they did just that. Egypt didn't just fight to free itself, it fought to outright annihilate the Hyksos. They didn't take vassals, for a change. All captured Hyksos, even women and children, were enslaved. The city where the fleeing Hyksos armies fortified for their final stand wasn't just taken and vassalized, as would be the usual course of action, it was razed.
And indeed, after that, the Hyksos completely disappear from history.
Mind you, I'm not saying that the Exodus story has any base in reality. It doesn't. It's just fiction composed during the Babylon captivity to make a "God freed us before, he'll do it again" point.
All I'm saying is, well, when talking about 3000+ years of recorded history of pharaonic Egypt, I would be wary of making absolute statements about what they would or wouldn't do. While, yes, we can say that 90%+ of the time the Eyptians would obey a certain code of Ma'at and would do that or wouldn't do that, at times that prescribed order fell apart rather spectacularly and brutally.
Would they normally wage a totaly war against an ethnic group? Well, no, the notion would be very strange. Did they do it once anyway? Hell, yea.
So basically, yeah, I'd focus on the specific Exodus story being unsupportable, rather than absolute statements about what they would always do or wouldn't ever do.