Fair points.I'm more focused on the facts and first hand evidence, rather than belt color. the pass works. I'm also a brown belt and I've been using it for years and I've seen it used and taught hundreds of times. by high level dudes (Saul, xande, Rigan and jean Jacques, bob bass, Chris haueter to name a few).. if I've seen it work zero times, I think there'd be more of an argument.
it was later revealed that Keenan's point when he said that pass "doesn't work" is that he feels that pass doesn't work against the highest level practitioners in competition. and maybe he's right. I'm not near that level and it seems that various standing passes are the popular and effective passes at that level. I think Keenan just off base when he flat out said "this pass does not work" etc. he went on to say that he'd armbar, break down or sweep the guy on top every time. he probably could. he's one of the best in the world. but 99% of the people can't do what he does.
Also not to hijack the discussion but I also think people focus way too much on doing only what works at the highest levels. It's a statement repeated by a lot of champions in our art/sport, and it's taken as gospel, but there's some nuance there related to your post that I think is often missed.
I think what most of these guys really are trying to say is to focus on stuff that can work against experienced grapplers and not just a bunch of club/hobbyist colored belts. However, I think it can be equally problematic to ONLY work on the stuff you see in the Mundials finals or the ADCC finals. Those guys are so good and are using such specialized strategies that I think you can end u missing out on a lot of useful movements and positions.
Plus, those guys at the top have had their periods of ownership of their jiu-jitsu and finding what works best for them. I think there's almost a fetishization of copying the techniques used by the highest level guys in the highest level matches with the most at stake. It's not a bad thing to do, but it's not the only thing you should do.
In fact, sometimes I wonder if more people would benefit from copying guys that are actually slightly underneath the highest tier, because the best of the best are technically outliers, and it may be more worthwhile for you to study and emulate the level just underneath that. I'm not sold on that thoery but I heard it recently.