The EP of this game said in a video interview in the last year he himself plays lotro on a 4k monitor, would like to get all these issues resolved, and they're working on it. For an ETA I have no idea and can only assume it's a non-trivial matter re-hauling systems created (for the alpha and betas of lotro) in the early 2000's. Maybe once the 64-bit client gets stabilized they'll have more bandwidth for this, no idea really though.