Reply from old man with some experience
I've owned a lot of vehicles - done all of my own brake jobs - have done a lot of friends too,,,,,,,,,
On a good 90% of these (The disc brake ones) I generally replace only the pads once they are down to the minimum thickness - I do all four even if the rears are still good. I usually don't do anything to the rotors.
When it is time to do the second pad change; at that time I replace the rotors too.
For squeeky rotors (slight glaze) I take the truck out in relatively deep sand and drive around engaging the brakes often. Usually roughens up the rotors enough to take care of the squeeks for quite a while. This was necessary on the Land Rovers because the brake sensors would give me an ABS/ETC/ fault due to the squeek.