If Zucman is a fan, this is great news indeed. A 25% minimum tax on billionaire wealth sounds great, and with broad support, as the article notes (even 51% of Republicans).
Much better news, too, for those of us who only saw this part reported on til now:
The campaign spokesperson called the move—which would still leave the corporate tax rate lower than it was when Trump first took office in 2017—a “fiscally responsible way to put money back in the pockets of working people and ensure billionaires and big corporations pay their fair share.” (emphasis mine)
IIRC, the corporate tax rate was slashed by Trump from 30-something percent, maybe 35%, to something like 18%, so to see that Harris was not interested in reversing this Trump tax cut fully (only to 25%) felt til now like yet another depressing instance of the ratchet effect, where the right does what they do, and neoliberals only undo part of it when they are in power.