So yeah, more in-state recruits will stay home.
But I also don't think every LDS player will suddenly flock to BYU. There's a good between the Oregon/Alabama tier and the Utah/soon-to-be BYU tier that is as large as the gap between current Utah and current BYU.
It'll help but it won't be a sea change. Too many people assume it'll be one of those extremes (nothing or everything)