Granted the Twitter feed is the only info I have read on it so I might be missing something, but at face value it just seems like kind of a poor decision for a few reasons.

1) He's an expected starter at Safety, and while it can be good for England, Lee, and Anderson to get some extra reps, IIRC of the current safety Depth Chart the only 2 with decent playing time were Hannemann and Hadley (I know Wilcox played some but is back to his natural position of CB with Akile Davis going back to WR).

The rest of the listed depth chart

SS
Behind Hannemann we have

Fowler (Hurt but probable) RS Sr
Jacobson True JR
Baldwin RS SO
Hifo RS SR
and little Hannemann True Freshman will be here in fall

FS
Then behind Hadley we have

Anderson True JR
Lee RS SO
England True Freshman
then Ah You won't be here until fall

So the only healthy safety with much in-game experience will be Hannemann.

2) We already have a pretty decent stable of HB between Canada, Hall, and Burt (who I would hope would get a lot of reps after red shirting last year) Dye to HB could be a gamble that could pay off, but I think with his size the slot is a better natural fit for him considering the other HBs ahead of him and the lack of experience of the current slot receivers (though Shumway should be really good). And I was surprised to not see Warner listed as a HB after being so excited last year to be able to play both directions, and that promise during his recruitment being a big reason he chose to come to BYU according to him, and having decent talent behind him at CB leaving less of a talent gap than Hadley likely will.

Like I said, I likely only have a very small amount of the reasoning, but I did find it a little odd. That being said, overall I do like Kalani's coaching philosophy of getting the best 11 guys on the field regardless of tenure or current position. Bernard paid off big, so it'll be interesting to see how it all comes together this year.