You know that Nasdaq isn't in Silicon Valley right? Lots of companies are based in the valley, listed in either CA or Delaware and go on to list in NYC now. There's no compelling reason for them to move to Texas.
As for the compliance thing it remains to be seen, but generally companies in low-compliance jurisdictions trade at a "fraud discount" to compensate investors for the likelihood of untoward shenanigans that would be prevented by that compliance.
Stock exchange aside, being able to build buildings without getting held of years or even decades for an endangered tree frog, and also employees being able to afford housing are kind of important to companies. Texas has its downsides, for sure, but it would be silly to pretend there aren't other reasons for companies to move there that have nothing to do with the new stock exchange.