In my personal opinion, people should be allowed to be re-elected. I find it perfectly fair! There are a lot of people who come and go, and if someone from the past has come back, and they work hard and deserve to get MOTS again, then so be it.
Now, I thought of perhaps limiting them from winning it more than once in one year, but I went to look to see if there was any repeating of names. If we look at the previous MOTS in the hall of fame, there has not been a year we've had the same person get a MOTS twice in one year since 2014! It would be a redundant rule.
Are there people who show up between different years? Yes, and in my opinion, they deserve that if they have stuck around this game for that long and have made a continuous effort to be a helpful member of this community. That is dedication that should be awarded, and that goes beyond being listed in a Hall of Fame. If they can manage to get nominated and win more than once in a fair manner, that says something about them.