Certainly many players in the history of MLB, especially those in pre-prime, early prime or mid prime, bounce back from a "down year or two" and go on to have "normal" or "better" seasons.
Sure, the reason the dipped at an unexpected time on the age/production curve (like so many Sox players last year) could be "wear and tear", but it could also be non-severe, injury related, personal issues or many other reasons.
Maybe we're arguing semantics, but I, for one, am expecting more upticks than down ticks or leveling out from these young Sox players:
Betts
Bogey
JBJ
Beni
I'm expecting 3 out of 4 to have a significantly higher WAR next year.
Call it age curve expected, call it random, call it "positive regression" or call it whatever you want, but I'm thinking it happens for the Sox this year.
Hell, we may even see upticks from HRam, Moreland and even Pedey, when he returns.