If I ever buy a new tractor, I would only change the oil in the transmission earily, to put synthetic in it. Otherwise, I would not change it, until it reaches the regular 250 hour interval. Even 250 hours is nothing, unless you operate in extremely dirty conditions all the time.
The oil that came out of my tractor at 50 hours, was brand new. (It only had 50 hours on it). It was clean, and clear. That's what the filter, and screen are for, they did a wonderful job.
Many manufacturers have eliminated the 50 hour, it's old school thinking. MF should too.
Yes, some will say it's necessary. You have at it then. But, why wait until 50 hours? Why not do a 5 hour, a 25 hour, and, again at 50? And then, every 100? Why? Because there is such a thing, as too much. I believe the 50 hour is also too much.
As far as the dealer offering to provide the labor, that's nice. But, there is an old saying about if you want things done right...
No one will put in the time checking the entire unit over, that you can. It's not hard work, and it's important.