Mmm... That wouldn't work either, since right after the rework (7.6) was also right before the all-around tank item nerfs that hit in 7.9. So because they wanted to make absolutely certain that tanks would never be meta again, they've been doing what they can to remove defense in favor of damage. For some, like Galio, that's meant flipping their primary and secondary roles.
So we can't go back to that Galio.
Although the one we have, the one they wanted "back", doesn't work all that well either. Since the items his entire kit revolved around-- Athene's and Banshee's Scepter-- were changed. Which means they're forced to make him more of a glass cannon because the items that granted both MR and mage amounts of AP don't do that any more.
So what can they do? I'm not sure. But a full revert wouldn't work without also reverting every change to every AP and MR item.