Looks like he is gone. Personally, I think his film was impressive and he was an under-the-radar player who wasn't heavily recruited because of his injury his senior year. No need to downplay his talent. If Bronco offered him, clearly he felt Chasen could add value to BYU's solid defense.
Luckily, MLB isn't a position we struggle to recruit and this opens up a schollie for this year, when we're already pretty limited in available schollies. I don't think this was a issue of him seeing greener pastures. I think he started to realize that it would be an experience to go be with his dad. I'd probably do the same.
Hopefully we all wish him well instead of mocking his talents or decision.