I don't know, but I'd speculate that the 25" variety was just more plentiful. functionally, they're the same, it's just the original monitors probably just got toasted from every day use. half of my games came from route use, or they sat in storage. they have less mileage on them, all the monitors look great. one's a K7000, rest were Polos. then there's a couple Blitz machines we got last year at auction, those monitors were absolute junk, a U5000 and a K7500. that's what would have come from a GL. now the K7500, I had that rejuved last year. after capping it and changing the flyback, it looks mint now. the U5000 is due for the same treatment.
that said, those monitors from the mid-late 90s generally just had garbage tubes. nothing more to really read into it, just the 25" replacements were more common than the handful of 27s. as history showed, the 27s more-so shifted into the tri-sync realm after that, and you know how pricey those can get.
otherwise, I don't know. it's not like anyone was really talking about tube swaps or cared about rejuvenating or had half the knowledge about shit with these we do now and the like back in the 90s. lol
the Neotecs, permitting that's what it shipped with, I think usually had garbage tubes too. just saying.