If the same density can be achieved you can imagine how much simpler the entire device would get with just a transparent screen – you'd have to move the rest of the electronics into the edges but that seems very doable.
1) The reason that the resolution is so high on the AVP is because it uses Micro-OLED which is also known as OLED on Silicon i.e. there is a layer of silicon behind the diodes which would block the light.
2) Transparent OLED TVs required a motorised screen to put a black panel behind the display. Only options are that or electrochromatic glass. Both of which are not black enough for watching movies etc.
well, its more that they managed to get them efficient enough not to melt/produce useable brightness.
But the actual biggest issue is optics. You can't just slap a transparent screen where your glasses are, and be able to see an image. You need to correct the image so its focused almost at "infinite".
Thats why wave guides are a thing, they (simplistically) project an image as if it was focused further away than is actually was. However, they aren't very efficient, which means you either need to dim the outside world, or overdrive your LEDs so they only last a few hours(and melt your face.) They have other issues like rainbow artifacts.
I think Apple isn't really interested in VR though, so they might accept some light bleed in a "just glasses" form factor Vision product.
For a different product that's glasses instead of a VR headset, sure, it might work (although I don't see why you'd want to go semi-opaque at all with glasses really, it won't be close to an immersive VR-style experience anyway?)
AR and VR have always felt like duals to me - with AR, you just put something behind it and you have VR. With VR you do passthrough video