Revive removal
Was it removed for lack of use? If so why not just lower CD by increments of 30s until it was used again? It made for some interesting niche strategies, and could be expanded to more champions if the CD wasn't so long.
That said, are summoner spells on the table for balance? I've seen so many good suggestions on how to tweak unused spells that seemed fantastic and the only one I ever saw go through was the change to heal last year. However, the change didn't even solve the problem with heal vs barrier in that they both fulfill the same role. You just made one better than the other. Why not make heal more of a sustain summoner spell that grants a % of health and mana back with slightly lower cool down and keep barrier as the "in a pinch" spell. Why not give clarity a mana regen buff? Why not do any number of the clairvoyance suggestions people have made? I don't think any of these suggestions would be game breaking and would simply add a reason to actually pick other summoner spells that could be integrated into a player's strategy for the game.