E. Liddell composed on 2021-08-06 15:33 (UTC-0400):
I've never seen an internal drive change its device node without a hardware change, but I suppose it would in theory be possible for it to happen if the system for some reason initialized an external drive attachment point first, or a drive ahead of it in the initialization order failed so hard that the system could no longer detect it. Regardless, I would class it as highly unusual on a system that doesn't have hot-swap drive bays or the like.
It was not unusual, before refinements in kernels and storage drivers made it less common, on motherboards with both PATA and SATA controllers, to upgrade a kernel or switch to a different distro, and have the device names of drives on the disparate controllers flip-flop. Changing the BIOS setting of PATA vs SATA priority could do the same, so a flip could come out of nowhere because the CMOS battery died and was changed.