Choosing between two keystones who theorically do the same thing but who dosen't apply in the same way and a third one that more than a vast majority of the mage roster can't proc regularly isn't satisfying at all.
Bruisers got their missing keystone in precision. Domination got one too because "why not". But I believe mages really deserve to get a new one in sorcery.
Comet isn't relevant enough without cc.
Aery got nerfed so often it basically became a pure support rune.
Phase Rush isn't even designed for pure mages
I'm not saying present Sorcery keystones are bad. What I'm saying is that for a supposedly mage-focused tree, sorcery dosen't offer much in terms of keystone variety for pure mages. It's either more damage with a chance of missing, more damage (but less) with a 100% hitrate, or movement speed that you can't proc on a regular basis. Filling the hole in the mage-focused keystone roster should be top priority whenever future big changes are going to hit