If the legislation survives for 50 years (it's not quite halfway there today), I'll accept it has passed the test of time. Until then, I'll likely continue to view it as a mistake but likely not for the reasons you expect.
Quoting from the Wikipedia page[0]:
> Between 1994 and 2010, the court had ruled for whistleblowers in only three of 203 cases decided on their merits, GAP's analysis found.
3 cases out of 204 means the court upheld 1.5% of Whistleblower claims. I find it extremely unlikely only 1.5% of claims had merit, or that only 1.5% would have succeeded in more conventional proceedings.
Anyone who throws away centuries of legal precedent in order to introduce a new legal concept to "improve things" and then produces a result that almost certainly provides worse outcomes for those it is supposed to protect was not, in my opinion, the once in a millenium legal mind that individual believed themself to be.
Given the high bar it needed to achieve to justify overturning centuries of precedent and the low bar it actually achieved, I think the Whistleblower legislation, as implemented, is an empirical failure.