If you're a top 2 pick in the National. Football. League. and still need an ego boost, I'm not sure that's a good thing.
Look, whether a QB sits/starts depends as much on the situation the team is in as anything. Sure, if CJ looks overmatched and struggles hard in PS, he might need some clipboard time to start. Mahommes sat because KC wasn't in desperation mode at the position, and they did win their division with Smith under center. Rodgers sat 3 years behind Favre. But there's just as many examples of QBs starting from day 1 and turning out just fine.
The Texans don't have a QB in front of CJ who's going to lead them anywhere, so if he looks halfway competent during camp and PS, he should be starting day 1. Not saying the Texans are ready to go anywhere or that CJ is would be leading them there this year, but IMO and in this situation, getting the game speed down, getting the experience and rookie mistakes out of the way and learning the game now could be off the charts valuable next year when they might be ready to go somewhere. Probably a lot to do with coaching but Trevor Lawrence's rookie and sophomore seasons were night and day, and he started from day 1.