Wee John didn't quit; he's in the baaack!! That said, I don't know where he sits on design and implementation, for the V2 bridge and 4005V would never have happened under Wee John.I believe there was a time when they upgraded the old bridge into a more sturdy version. Not the newest roller bridge, but should still be better than the earliest bridge.
In 2006 or so, they introduced the vintage push-pull switch so that it can emulate the 4001 tone. Mine is from 2008, and I almost always use it in the "vintage" position for a Chris Squire tone.
In 2020, they received a complete overhaul after John Hall had quit. New dual-action truss-rod, new ultra-sturdy roller bridge. There was a year or two with an unfinished fretboard, but I think they've gone back to a finished one now. If I were to start again, I'd definitely buy the newest version.
4002V next!