It's probably more-so to do with the feast or famine right now of healing as a scholar. If the tank isn't properly mitigating or even just under geared before you could somewhat make up for it with being good with your cd management but it isn't usually the case anymore.
Now its either you have them topped off most of the time cause things are generally going well so you try to spend all of your AF stacks to charge your faerie gauge to be efficient and it could accidentally lead to just not having AF when the encounter ends (which isn't actually the biggest problem cause everything is currently fine), or it's the other side of the spectrum where everything isn't well and it only take 1-4 instances of a few mess ups and suddenly you have to blow everything to keep people alive and then it can be a real struggle for awhile. It's the situation where people mess up where you would rather have the "whole" of your move kit from the beginning so you can excognition before the fight so its cd it up before it ends or simply have your entire moveset from the start.
The mp issue can also start hitting a bit if you're forced to repeatedly blow everything or even sometimes on a "middle of the run" run simply cause people don't usually want to wait for the entirety of the mp gauge till fill out (scholars included) before the next encounter, that and in combat if you're constantly healing and using spells your natural net mp is going down even with the mp regen available depending on what skills are used. This can lead to having long drawn out fights steadily getting worse for people which compounds the problem so a means to slowly counter it would be nice.
As for whether or not it has to be an mp regeneration move though alot of people are generally debating that while trying to be fair, however the general thought on it is just to return it to how it was cause it has been shown to work rather effectively, some people think it could be replaced with another ability entirely (some people have suggested an instant crit shield or a buff/debuff of some sort to stay in line with healers not needing to do damage). As long as it was something to spend your AF stacks on when you do have that free opening when everything is going well and there's no need for the other heals
all of this said however the mp "can" be an issue but generally its not what the main problem is, it's generally the moveset not being there and having to miss out on building the faerie gauge and the utility of having your kit available. The last thing any scholar feels good about is having the tank start pulling a room and they run slightly out of reach where your normal healing casts cant finish before they leave your range with your instant casts being tied to AF and the whole group starts suffering because of it.