As person who primarily plays mages, I would just like to say that these changes are bad.
Assassins aren't really struggling that much as most of them maintain positive win rates with the few who are struggling traditionally doing so.
In addition, no one in the community wants these changes. Mages aren't even really that busted. You know what we want you to address though? Bot lane.
Overall, these changes won't solve anything. In fact it's just causing more problems *cough* Goodbye Item Diversity. Hello Archangels Staff *cough*. So please, just leave the damn mages alone and focus on the real problems of the game, bot lane/snowballing
Tldr; Stop gutting mages and start looking at bot lane.