stupid question abt nitro tag changing?

i realize if you change your tag/ID number with discord nitro and then your nitro subscription runs out, your tag is randomized -- But what if i like the tag i have already, and i never change it with nitro - if my nitro does (accidentally) run out, will it still be randomized? or do i keep my tag because i never actually changed it?

[if this has been answered before i apologize, i tried looking for answers and just kept getting threads about people not knowing the tag wouldnt be kept after they changed it. i couldn't find the answer anywhere else so that's why i brought it here.]