I have to say, I don't really see why they didn't just cut those parts out in the first place.
But anyway, I do actually really love the Porygon evolution line, I find it a bit sad to see that we haven't seen a very Porygon based episode since then.
Obviously we won't be getting it any time soon, I can assure you of that considering the whole far away region with completely new pokémon. It could maybe happen in a filler season or maybe even an ark to promote some sort of upcoming game.
And also, i'm sure they wouldn't be stupid enough to add more of those bright lights and cause that problem again.
If we were to see it return I heres my idea for an episode;
Ash, Iris and Dento find themselves on Route 17, they notice the "P2 Laboratory" and decide to take a look in. They notice an old Team Plasma member and he tells them about the Genosect revival thing. Then he shows them his Porgon 2 and want to evolve for -insert reason here- they go out trying to find how to evolve it and find the Dubious Disk then gives it to Porygon 2 and it evolves.
I know it's kinda suckish but it fits in well with the games plus you can find the Dubious Disk in the P2 Lab in the games so that could be a reason for Porygon.