I'm certain Limbus changes will happen eventually but it darn sure is last on the torevamp list. It's probably right behind ToAU content. Limbus is sort of the step child of the bunch due to Sea limitations(getting there through CoP missions) Dynamis and ToAU content is a bit more pressing ever since Empyreans came around and SE has been trying to make relics and mythics easier to obtain. Limbus for the most part has obsolete rewards so there's really only so many people bothering. But I see no reason whatsoever for Limbus not to get the revamp treatment to make itself along with everything else relevant again at 99.