Soraka and Sona nerfs will not fix the issue with top

All that will happen is other supports that have a similar skillsets will work their way into top. The real reason Soraka and Sona were top isn't because those champs were overtuned or anything. It really as NOTHING to do with champions period. It is because TOP as a WHOLE is the most useless/ non influential lane in most games. The game quite literally is who controls bot/Drag. Yes some games are won via top, but usually that is when both bot lanes are doing bad (this rarely happens). The way to fix it, in my humble opinion is to nerf drag OR buff Rift to have some sort of global game influencing buff. Rift is a great thing to get, but usually rifts are a result of a jungler being super ahead (usually via ganks mid or bot) not really because top did anything worthwhile, or the team as a whole did anything worthwhile.

So to wrap it up. Soraka/Sona nerfs will not fix the issue top.

Now we will get different champs that abuse how weak top lane's influence is.

Please just nerf drag or buff herald. If you want to keep the pace of the game where it is at, then buff Herald. If you are ok with slowing down the pace of the game, nerf drag.