S.T.O.P
Strategic Team Objective Plays
The towers are zonyas every X amount of time aka not targetable for x amount of time so the team has to base kills around when you can take towers down and push objectives that's when the plays happen. To spice things up it can happens randomly so you don't know when objectives will be available to take. so it punishes tdm as it requires teams to coordinate more than normal because if you die right when towers go open you lose towers ofc.
as for minions i guess they could be zonyad where ever there are when objectives get froze if you play strategically you can setup a wave before it gets froze to push hard in your favor.
Some things they could do to add more to this gamemode.
1.new summoner spell(called S.T.O.P) :p that lets you force nearby objective untargetable 1 per team cd would ofc have to be balanced by riot. 2.give jungle monsters smite buffs for this gamemode. I cant think of anything but im sure the creative minds at riot could come up with some amazing stuff. 3.increased minion spawn rate so games aren't long on a featured gamemode or make minions worth more so games end sooner like every other game mode this would have to be balanced to good point. 4.make jungler monsters spawn more often another source of gold income while lanes are froze and people wont be doing nothing while you wait for lanes to unfreeze also hence the smite buffs.
I honestly cant think of anything else but I would love to hear if any rioter likes my idea it would mean alot to me :)