Maybe... depends where weight is added and removed, and how much. Most cars aren't particularly prone to flip in the first place, and a few hundred pounds probably won't make a huge difference. (ICE cars vary in weight depending on whether the gas tank is full or empty, and it's generally not an issue.)
I've heard that having more than 50% of the weight on the rear wheels is dangerous because if you lose traction on a corner it's the rear wheels that would lose their grip first, which is hard to recover from, whereas if the front wheels slip first it's more self-correcting.
I've heard that having more than 50% of the weight on the rear wheels is dangerous because if you lose traction on a corner it's the rear wheels that would lose their grip first, which is hard to recover from, whereas if the front wheels slip first it's more self-correcting.