It is realistic that Utah kind of approached him and said frankly... "Listen, if you want to be a DE here now, playing time may be tough to come by with the young guys we have. You'll get a chance, but switching to DT or delaying a few years by taking a mission would line up better for you and for us"

That's exerting subtle pressure to get him to do what Utah wants, with the caveat that you've increased the chances of him going somewhere else since you're telling him the fit isn't great.

Best guess is that Utah judged that pressure would be more likely to work out for them than to result in them losing a stellar recruit. That honestly fits all stories.
Moa's offer wasn't revoked, but yeahs Utah's lack of interest (in him as a non-mission DE) also opened the door for other universities and explains why he felt the need to stipulate that his offer hadn't been pulled.