My instinct is also to assume they didn't reset their phone, but I also assumed Apple deleted their photos when they deleted them years ago.
I wouldn't be shocked to find it there's some technical cruft around it being a built in mandatory app, and corrupted data was retained.
In fact, when I think about it, if I wasn't biased towards Apple, my prior after a bug involving photo deletion should be to expect bugs involving photo deletion.
My instinct is also to assume they didn't reset their phone, but I also assumed Apple deleted their photos when they deleted them years ago.
I wouldn't be shocked to find it there's some technical cruft around it being a built in mandatory app, and corrupted data was retained.
In fact, when I think about it, if I wasn't biased towards Apple, my prior after a bug involving photo deletion should be to expect bugs involving photo deletion.