There is very little to no research comparing the pros and cons of overseeding. But it appears that ryegrass or other overseeded cool season grasses may compete with the permanent grass, particularly centipedegrass. I have seen a number of centipedegrass lawns that were severely weakened during spring green up as a result of the competition with the well established ryegrass. The extra fertilizer may also cause problems for centipedegrass, possibly inducing centipedegrass decline The main reason most people overseed is because they want a green lawn during the winter.
Personally, I’m ready to put my mower away for the winter and I take a break and my lawn takes a break. But this is a personal preference. You’ll have to make that decision.
It appears there is the possibility of causing some problems for the permanent lawn grass, particularly centipedegrass, as a result of overseeding but I can’t provide legitimate research to show this. It’s based primarily on observation.