The Horns and the Aggie can answer better than I can, but IIRC they typically played their game on the day after Thanksgiving.
We played Nebraska on Thanksgiving weekend for quite a while. The 1971 GOTC was on Thanksgiving Day.
There was a decade or so (maybe more, maybe less, going strictly off the top of my head here) where UT/A&M occupied the T+1 2:30pm slot, on a different channel than LSU/Arkansas on CBS. I remember these well because I was usually at my uncle's house during the Thanksgiving weekend, they're mostly Aggies, and there was always tension about which game was the main priority in the living room. Some years they had other things to do, the women would go get snookered by Black Friday "deals" and the men would go hunting or doing upkeep on their leases, etc., and the big TV was all mine. In which case, damn the Aggies and the Horns, we're BBQing pigs. Other years....well, the women were still out Christmas shopping on Black Friday, but the men were home eating leftovers and watching football. In those years, I usually had to find a smaller TV in a bedroom by myself to watch LSU.
Honestly, I didn't have enough awareness of Texas teams back in the day to know they played on Thanksgiving for years. I remember utee saying something about it here years ago, which was news to me, and then when A&M joined the SEC we eventually started playing our games @A&M on Thanksgiving, which I didn't like, but the Aggies thought they had a tradition, and as usual, when other SEC schools claim they have needs and traditions that need satisfying, LSU is going to get shafted and screw whatever the school or its fans want. I'll digress on that. On the @LSU years the game was on Saturday. That was a small bonus for me, because I never liked the T+1 games with Arkansas, so while we played on Thanksgiving every other year, we also got our Saturdays-in-Death-Valley back in the in-between years.
And now we end our seasons with Oklahoma.
We shoulda never let Tulane leave the SEC. We'd have an in-state rival today to end with and wouldn't get jerked around trying to be forced to be every new guy's "new RiVAlz!!!"