Texas never publicly announced/posted/released their 2023 schedule. It still defaults to 2022. I think they simply retweeted the Big 12 on the schedule release day.
Oklahoma did post their 2023 though.
2023 Football Schedule - University of Texas Athletics
The official 2023 Football schedule for the University of Texas Longhorns
texassports.com
Oklahoma did post their 2023 though.
2023 Football Schedule - University of Oklahoma
The official 2023 Football schedule for the University of Oklahoma
soonersports.com