I have the same opinion with respect to my son (although in my case it's more academic, if you're excuse the double-meaning, because he's not playing at nearly the highest level, so it's not even a concern about missing out on anything promising soccer-wise). If I thought that soccer was significantly impacting academics, he'd be out immediately, even if that meant leaving mid-season and eating the rest of the annual club dues.We are trying it now in middle school so we can determine if it's something he wants to continue in high school. Academics is the primary focus. If MLS Next interferes with academics then we leave.
I'm also sorta conflicted on whether or not, as an academic argument, I'd want him to play at the highest level (ie: MLSN or equivalent) even if he was capable. I don't want him to feel like it's a job, and it certainly wouldn't have priority over things like academics. For better or worse that's not a call we've needed to make, since he's not that good, but it would not be clear cut for me, and I know some other parents who also struggle with this (eg: one of the other kids in the club, who plays NPL, and has been invited to attend some international events, with expenses paid; his parents do what they can to support him, but I know some of those are harder decisions).