Note that some states with almost similar number of electoral votes are going in the other direction. Florida is becoming more safe red all the time, and PA is a swing state and might become safe red at some point.
That's what it flipping would mean. TX was purple. Then it became red. Its demographic trends[0] show it coming into play again.
The good news is that under a national popular vote, a Republican could probably survive a narrow popular vote loss in Texas or Florida and still win the presidency, because every GOP vote in those states would still count toward a national popular vote majority.
https://www.politico.com/magazine/story/2019/08/28/gop-natio...
[0] At least as long as the Republican Party is adamantly anti-immigrant. https://www.texastribune.org/2019/06/20/texas-hispanic-popul...
To say it a different way, at some point if the democrats gets popular enough they win every state. That doesn't mean that every state is a swing state, just that people are fed up with that party.
Long term the demographics are not looking good for Texas GOP, based on current voting trends. Most likely the party will adept and come up with new policies to attract different voters. Or you know suppress the vote and rig the elections.
If Texas manages to finally flip during this presidential election, though, I'd say all bets are off and the NPVIC might finally become law of the land.