Yeah, that's probably not too wrong, but it may not have been only the conference move. There are a lot of good players in TX and NU's peak Texas recruitment during the Big 12 days was at a time when schools like TCU, Baylor, Tech, and A&M were also picking scraps. All (well, most?) of these programs have taken their turn becoming legitimate P5 programs since then, and Texas remains a force. Houston has also emerged. So, it's become a much more crowded space than it was when Nebraska as a B12 North competitor could swoop in and claim what Texas overlooked.
And those days, Texas was hosting a junior day and filling half its class. These days, Texas is doing as much late game recruiting as anybody. Their class this year is poised and reliant on major late moves.
It's also the coaches that are different. I don't know if Nebraska is totally not a presence in TX anymore (the recruitniks here can speak to that), but our major connection to TX since 2008, Tim Beck, is now at tOSU. He's a former TX HS coach and was always a recruiting force here.
In contrast, a number of our current coaches have a *very* heavy California/Pacific Coast presence, while a few (Stewart, Hughes?) are East Coast guys. Coach Williams has ties to SEC country. For Nebraska, The Game used to be local+Texas+elsewhere. I suspect while Texas is still in the picture, the focus has spread around more, and TX recruiting has taken a backseat to at least California if not a few other areas as well.