My only issue with paladin getting a gap closer is that there's a good chance it will become just another oGCD attack that you hit when it lights up rather than being used in a situational way.
Let me give you an example of another game with gap closers:
SWTOR (Star Wars the Old Republic)
All the tanks in that game have either a speed boost or a plunge style move to quickly get them to an enemy. But in that game, it is not used for extra damage, in fact for the charge moves that deal damage, you can't even use them unless the opponent is a certain distance away. Meaning that when a boss is in your face and you're fighting them, it's not even a button you can use if you wanted to since you can't get the requisite distance away. The purpose of the charge moves isn't an extra attack, it's used specifically for mobility to quickly get back to a boss when you run out or to very quickly pick up an add before it noms on your healers.
But that was also a game with significantly larger battle arenas (seriously, they're double to quadruple the size of the FFXIV arenas) and on higher difficulty modes the adds in the raid encounters would one shot your healers unless you were on that enemy near instantly. It was a game where mobility mattered due to arena size and danger of the adds in the encounters. But in this game? Adds don't move for a few seconds to give your tank time to grab them and the boss arenas are absolutely tiny so having that mobility isn't really necessary in PVE. PVP I can see why you'd want a move like that, mobility is absolutely important in that content.
But to boil it down to my main point, if they're going to give pld a gap closer, I don't want it to become just another oGCD attack that we hit and since mobility isn't as critical in this game's current high end PVE encounters (I've completed nearly every savage boss this tier, only one I haven't beaten is O12s which I am currently progging through. There is not a single case where I can think of a gap closer being useful for it's intended purpose) I don't think a gap closer is necessary. Also if they want it specifically for an extra oGCD to buff pld's dps, I don't think it's the right way to boost it.