You're right that BYU isn't getting talked about for NY6 or CFP, but BYU gets talked about a lot because their opponents are all relevant. When Boise gets brought up as the assumed G5 NY6 representative, they talk about how Boise is likely to get in if their only loss remains a loss to a very good BYU. BYU's hail mary in Nebraska is still talked about when teams are driving down the field late in the fourth quarter. I've heard analysts talking about UCLA and whether they still have a chance to win the South, and they bring up their win against BYU. Now that Michigan is getting more and more chatter, they talk about their game against BYU (which is the only exposure on here that sucks).
BYU is still getting discussed. You're kidding yourself if you think that they aren't at all relevant.