They banned destrucive research for new rooms, because some researcher decade ago, enthusiastically drilled a bunch of holes to nowhere in order to do find them.
They still allowed the non destructive muon imaging a few year ago that heavily hinted to an unfound room.
The end result is that basically no one will be subject to this tax bracket.
It is high enough that everyone at that level will mainly get their real income from stock/loan which aren’t salaries.
Having this tax bracket or not having it is, basically the same for the super wealthy. The real method to tax them is through capital tax, not income.