Of course it would be easy, anyone could do it.
Is it worth it for an artist who's current job is remastering more than half the champions in the game to look remotely presentable in the new map (that is also being worked on by them) to make 30-40 custom icons that all need to be different from the current ones, show the ability's function and effect well, and be easy to read by quick glances? It's not, its why studios have priorities so they don't do this specific thing and make the way more noticeable and impactful changes take (even a bit) longer, because its a pipeline, and if that pipe is smaller, then its slower.