I think Van Halen might have about 10% or less of the demand Guns does.
Without any promotion, endorsers, sponsors, almost 0% media participation and no new music they have reclaimed the rock world.
This will never happen again seeing that Guns and the few bands like guns that are on that level are practically dinosaurs, it's a digital world now there won't be any rock bands of this magnitude again.
I think you misread the question. Led Zeppelin isn't "out now" is they don't exist currently. While I personally loved A Different Kind of Truth, there's no real demand for new Van Halen music. There is, however, a big demand for new Guns N' Roses music.
From 9-6, the only MC with the flu, yeah i rhyme sick, i be what you're tryna do, made a fortune off Peru, extradite, china white, heh-ron, n!gga please, like short sleeves i bear arms, stay out my way from here on, clear? gone!