Yes, that’s kinda what they said here. Its expensive to do (given they didn’t plan to do it so nothing is set up to allow it) but they’d like to do it and if they do it’ll be a post-launch thing.
I’m not sure about whether I’d be OK seeing it as an mtx though. IMO it’s kinda a fairly fundamental thing that I’d have rather seen in the base game rather than something you need to pay extra for. It’s an interesting question, what would a person be OK with paying extra for as against being included in the box price (f2p games have somewhat more leeway in this regard as they don’t charge for entry).