@BonsaiNut, given the good nature here and the fact that we will all need to figure out how to deal with this, I'll keep discussing in this format unless or until it degrades. I do appreciate the good conversation.
I agree on NPS, but there are areas with good back-country trails on BLM, though neither compare with USFS and USFS is in review now. I expect they will approve pedal-assist bikes this year and regulate them exactly like mountain bikes. I expect they will request groups like CAMTB to help them police it and I also agree that they will have a really challenging time doing so.
As for speed, I have seen moto-like models and e-motos that go 60mph. Those look pretty obvious and do not look like pedal assist mountain bikes. That said per your point above, it could be hard to regulate given that at least initially the USFS will not know the difference, but that would work out over time and with familiarity to some degree.
I am sure there are some who feel as you mention--that this is an end run way to ride moto on bike trails, but I think that's a small minority, at least in my experience. Most e-MTB riders I know are mountain bike riders who either want an easier way up (call it cheating if you like) or are super-fit racer types who wants break on some days and I know lots of superb mountain bikers, pro level, who ride e-MTBs sometimes for recovery or for something different or to keep cooler on an 100 degree day or just because it's fun. Some just want to practice descents more and pick this rather than shuttling since they can get 2x to 3x as much descent in a given time.
Finally, the Santa Cruz and Specialized bikes, even hacked, don't have that much power. I've ridden a few hacked ones and on flat ground it's really hard to get them much beyond 28 to 30mph. Yea, that's fast, but not 60. And as soon as an uphill comes along, speeds drop a lot. There's only so much you can do with about 1hp. To get to the 60+ speeds most bikes use much larger batteries and much larger and more capable motors.
AS I said earlier on, I enjoy my e-MTB, but not as much as my analog bike so I ride the analog more. I am also fortunate that we have lots of legal e-MTB trails up here in SCV. We will all be a part of what happens next. I expect to see more e-MTBS and to see USFS allow them on bike trails and if that happens, we will all have to figure out how to deal with it and how to teach trail etiquette. As our sport grows, that will be one of our biggest challenges. We need to unify to advocate for more trails, more responsible use and broader access. Groups like CAMTB are here to do that. There certainly are powerful groups that want to eliminate our access in most areas. Being united and having great discussions that lead unity and to responsible action and internal policing seems to be the way to go to me.