Reason why Elminster, Simbul and other Chosen suffer from that condition, is because they remain to be Chosen, if though Weave collapsed. So where other spellcasters during 4e timeline was able to re-learn how to spellcast without Weave (more classic way, like spellcasters in Greyhawk, Eberron and all other settings do). For Chosen the only way to spellcast still was to tap into shattered Weave. Which was extremely dangerous. Elminster himself was able safely cast only cantrips and lvl-1 illusion spells. Simbul wasn't even as lucky. As Weave were restored, survived Chosen was no longer suffered that condition.
If Gale was Chosen but no longer is - he would not be subject of such condition at all, even if it would be 4e timeline. Not mentioning again how Chosen of Mystra even be a lvl-1 character.
