Wouldn't the Maj. Cmd selects be boosted by the fact that the Navy requires JPME to be selected, and that JPME can be done concurrently with a 1 year master's program at the NWC?
We're also talking someone who is 20+ years into his career before that little wicket becomes important vs. the importance of getting a master's as an O-3 on your post-divo shore duty. Apples and oranges?
Yeah, probably, though many certainly got it earlier.
Where it is/isn't important obviously depends on what your community values and timelines. For an 1110, post divo shore is considered the best opportunity whether it is Navy sponsored or otherwise, for various reasons which don't become apparent unless you think of it in terms of opportunity costs down the road.
If the selection rate drops enough and enough people have gotten their Master's, "tiebreakers" stops being a "tiebreaker" and becomes "why the fuck don't you have this yet?"
For example, if everyone else just does the JPME and Master's on their own time, and you're the only asshole left that needs it, your detailer will probably send you to NWC. But then you'll go up for a board with a NOB from NWC or NPS while everyone else was getting real FITREPs that year. Maybe it matters, maybe it doesn't. Board stats are a good way to figure out what your community does care about.