I don’t think he has anything to do with age. Having more responsibilities as you age and not going to as many games as you did when you were younger. Not as free to attend games now married with a kid on the way than when I was in my late teens/early 20s going often during the summer with my friends.
The only guys I can think of that the Sox could dfa to make room for MiLB signings are some of the older guys who may not have long-term value like Banks (he's 32) and Scholtens but they have options. I'm also not really sure if they would get picked up or not. Lambert and Peralta (just meh guys really) too I guess. Also depends on if Shane Drohan makes the team out of Spring Training I guess.
When people were comparing Fletcher to Eaton, I figured he was small and probably the same size as Eaton. Eaton is 3 inches taller, Madrigal 2 inches taller lol Altuve is listed at the same height (5'6") and he's hit for some power in his career.