new mage item plus ekko changes (wouldn't call those nerfs) sounds just as toxic as current Ekko

You can still play him tank ekko with next to no overall difference. will likely remain as tanky and if anything do more damage especially with a successful ult.

zhonya active is very effective on ekko. As if he doesn't have enough ways of kitting and stalling as it is.

the new zhonya will be less expensive and provide cdr. roa will now provide healing as well.

all his "nerf" were fairly compensated with. I would consider this more of a change/redistribution than a nerf. his Q lost base 30 dmg at level 5 but ap ratio is higher by .2 with zhonya and roa he gets this damage back.

its pretty much a draw when you build roa and zhonya. Except these items scale better on him overall. Even if all you build is zhonya and your Q might deal 15 less dmg, all his other spells will benefit, your ult is now also stronger and your shield is bigger and your passive scales better. even first dragon buff works with it better.

I expect more considering he's sitting at 57.7%% win rate top lane.