I'm pretty sure the Bendix was the only 2-speed "kick-back" or "automatic". Well, I think Sachs made an "automatic", but I don't think it was a "kick-back". The shift spring on the Bendix didn't really wear out; the little tab on it bent out straight, and it wouldn't shift. The cog was integrated into the mechanism; and when it wore out, the hub was pretty much shot. I've never been a big fan of the "kick-back"; it was heavy, draggy, and just a bit fragile. I've got a couple of the REALLY old 2-speed manual-shift hubs.
My guess would be that perhaps Sturmey-Archer(SunRace) or somebody else revamped the old Bendix design; since I'm pretty sure Bendix is out of business, and I imagine the patent has run out. It may be a bit different than the original Bendix, as are the new SA 3-speeds from their original counterparts. At this point I'm just speculating; I'll be stopping by my old shop this weekend, so I'll see if they have any of the bikes in, or at least any more details...