Yeah... was straight no for re-roll from the idea of it, still didn't change it. But anyway, let's go with this if.
From the beginning it was about investing money into those, which meant any random guy with an oil pipe in his basement could just own the game 5 days after he joined. And also, as a new player, I'd just turn my head around if I see someone can just invest money into creating perfect Pokemons, even if "only" legendaries. Hope this way isn't anytime longer even taken into consideration, since it beats every non-P2W ideology the game supported so far.
Now, PVP coins. Answer is simple: you constantly on the game, can constantly PVP = win and others don't. Now into elaboration. Let's say player X gets 600 games in a season, from which 450 are wins, which is a lot more than the normal average. He will get to keep investing those PVP coins into rolls and rolls. If it was PVP coins for a chance to recatch your legendary, I'd be all for it, since the game is for based on RNG since the begining of time. But this re-roll isn't RNG anymore, it's calculated RNG, which is a total different story. Back to the story, players who will keep PVP-ing will just end up having better and better legendaries, to the point where they will end up having almost a full team of legendaries on ladder (because they are legendaries and have their crazy BST and whatnot). New players/players who don't have time for playing that much will eventually get bored in keeping facing these kind of players and will just leave PVP, if not the game itself.
But oh well, if this would be introduced, PVP coins is a lot more viable than normal coins, since the player actually works for them and not just comes out of nowhere, and will mostly get players on the ladder in the near future, but in the long term, it would probably end like I described earlier.
So my final answer: no at all for re-roll, but if they were to be in, yes for PVP coins and no other ways.