I think it would be very surprising but I can see it possibly happening, I don't even think it really requires much imagination. Nikita doubtless thought he'd do much better with Viktoria than he's done. After 3 years together they have a total of 2 GP medals, both from last year, not even this year. Their results if anything are getting worse. For whatever reason they aren't able to train with the coach they wanted to train with. He can't even get on the World team; the Fed seems to think that for sure S/B have passed him. It's not easy to see a way they'll be on the Oly team. He wants to be on the Oly team. It's been 3 years for him to get over whatever negative emotions he had at the time of the split and think of things more logically. He may well have come to a place where he feels like OMG what have I done?
Getting Elena back on board with him might seem trickier, but she's not an idiot. It has genuinely seemed she's enjoyed skating with Ruslan and their coaching team, but she knows their actual results, which like Nikita and Viktoria's are getting worse not better. She hasn't even been on a Euros team in two years, forget Worlds. For whatever reason the move to Igor didn't work or was aborted; her current coaches have never had a team who won any major medal on the Senior level. If Nikita managed to approach her in the right way, and convince her that he was sincere, can I say I think he'd have an impossible time to convince her? No.