By the time the trans has that many miles on it, it definitely needs it. The problem is, as they say, that the worn out parts that are now working OK with the accuumulated crap in there and fresh fluid lacking that grit may allow things to start slipping and not working the way it is now. That's how it goes...
They recommend changing the fluid every 30,000 miles, so the more often the better. People not doing it in the first place is the reason the trans wears out. Changing the fluid after it's been neglected is kind of a band-aid at this point. It's still going to wear out eventually, it just depends on trans temp and use/abuse when you drive.