Yes and No.
Look, 3d printing is almost a psychological thing. You almost nailed it but skipped right past it.
The term proxy used to delineate between wysiwyg and non-wysiwyg. "I am using this chess piece as a marine" The Deoderant Bottle Gravtank from White Dwarf - Not a proxy. They made it custom rules. It was a miniature, and it was furnished with love and care. This culture is now only found in like, airfix or custom scifi modelling.
Modern GW has waged a psychological war on these things, encouraging game stores to do the same.
Proxy is now used, as you have demonstrated, to cover anything not GW. Even if its wysiwyg, its looked down upon, otherised. GW stores have even gone as far as preventing people from playing official GW minis that are end of life in their stores. Soon these will be referred to as like "official proxies" or something.
I have 2 local non GW stores.
Store 1: Owner does not permit unofficial minis in the store at all. Will rant about this policy to anyone who listens. He says there's no way he makes money on printed minis so screw them (I was in the store to purchase paints and brushes and so on for my printed minis when I caught this rant)
Store 2: Has 3 3d printers, sells printing services, sells resin. Doesnt give a crap.
But it doesn't matter in either case, because 40k players are policing each other. GW has shifted the language to otherise armies that even have converted 3d printed bits, let alone full prints.
Not to mention: 3d print resin isnt that bad. The 3d printer business makes a lot of money selling filters and tents and housings and gloves and what not at inflated prices. Some of these things are worthy, others are not. But I was using UV resins for SFX before printers caught on, and guess what, resin fx are smellier and less able to be hidden in a dark corner of your house. Not really a huge impediment. The terror about UV resin seems to be coming both from the people slinging the extra gear, and the people concerned largely with these evil "proxies".
Also, not to put too fine a point on it, but GW mostly makes money from new players. Old grizzled angry veterans arent their bread and butter anyway.
Give it 10 years, let more stores embrace 3d printing, let some more permissive games take hold, and then you might have a chance at killing gee dubs. But they will still be selling huge expensive kits to 12 year olds using mums credit card.