You seem to think that ED glass is some newfangled technology; it's not. ED was invented by Nikon in the 1960s for their camera lenses to cure chromatic aberration or at least attenuate it. The best material for negating CA in lenses is fluorite glass and there are camera lenses with such lenses, but they are very pricey. The issues with fluorite glass are: fragility, vulnerability to condition changes (hot and cold), and difficulty in making larger elements. All this translates to (much) higher costs. For photographers, controlling CA was critical and so, they would spend the money for these very pricey lenses. Of course, now that everything is digital, CA is less important because it can easily be eradicated in PP. However, for spotting scopes and riflescopes, where the image is used in real time, no PP, ED does make a difference. Riflescope makers started using ED elements in their designs around the turn of the millennium.
There are not many glassmakers around the world so most ED glass comes from the same few glassmakers. Nikon introduced Super ED some years back, which take the CA-attenuation capabilities of ED glass a little further; getting closer still to the capabilities of fluorite glass. It's in some of their camera lenses and now riflescope makers like March are incorporating Super-ED lens elements in the riflescope. If you have a scope with ED glass in it, the Super ED is just a tick better but in my case, it was not worth dumping my current March for a new one with Super-ED. If I were to go from regular glass riflescope to an ED glass riflescope, I would go straight to the Super ED glass.
You will not find a riflescope with fluorite glass. I think there was one but it was on a price level of its own and I think it's been discontinued. Fluorite glass just doesn't do well on a riflescope with its attendant shocks, hits and exposure to various changing conditions.
All advances in glass that we get in riflescopes are first introduced in camera lenses. That started with coating, multi-coating and fully multi-coated elements and then ED and Super-ED. Currently, there is nothing in camera lens glass that is new beyond Super-ED. We've already discussed fluorite. The camera lens maker may be cooking up a follow on to Super ED (Ultra ED?), but for now it does not exist. Coatings are always being worked on and improved but it seems to be all incremental eight now.
On the other hand, the camera and camera lens maker are concentrating on the digital components and that may well be what could come next to riflescopes. But if your hesitating buying a new riflescope because you're thinking there's gonna be a new glass paradigm shortly, I think you put that concern aside for now.
Then again, watch the riflescope makers come out with glass that pierces fog, mirage and the gloom of night next week and cheaper than ED glass.