The concept of a "Led Zeppelin but for Generation Z" makes them deeply dull to me.
The irony here is that if they truly imitated Led Zeppelin beyond the superficial aspects, they would develop music from a wide variety of genres, rather than producing one basic sound.
The real horror, however, has little to do with their musical style as such, but with their singer's voice. Imitating Robert Plant while not being naturally endowed with a voice similar to his will not yield good dividends. In interviews you can already hear some of the damage to his voice that's been incurred, and on stage he looks like he's in physical pain--no person's face should strain like that while singing.
In any case, I don't mind their music, but their taking off has really bummed me out; it gets annoying when people ask if you've listened to some exciting new band that you'd already heard of like a year and a half ago.