There is actually some evidence that iGens are less solidly D than my immediate birth cohort, although it could be a sample size issue.
YouTube transcript for this 538 podcast episode I listened to during my commute
There is a simple math issue here at play for Republicans- unless you start making sizable gains with a group of very very socially liberal voters, the problem you run into is that no one lives forever and gen Z is not any more conservative than Millennials really were.
Sure they can be more disaffected; you can say that they're a little bit more likely to prioritize economic issues maybe than social issues. But right now that generation still is backing Democrats in the average of polls too, by more than John Kerry won young voters by against George Bush.
So yes gen Z is different in a way that every generation is different. What's more interesting here for me is that they're as close to a continuation of Millennials politically as you can get from another new generation, in ways that did not exist previously. That's my take.
Short term, it might be helpful for Republicans that they are able to peel of voters that aren't quite married to the opposition yet but eventually, they will have to govern and if they take their soft support for granted, it will be as if all of their crossover appeal never existed.
It was very much how Obama was able to win with sizable majorities because he was able to peel off enough libertarian-ish but then he couldn't keep them because he had to reprioritize economic issues given the realities.