Twisted Treeline Update 5.13
Game length has gone up with the addition of this new turret, but it's a little higher than what we're happy with. We're going to quote the designer on this other context: "The nexus turret however, remains unchanged - a last bastion of hope braces against the inevitability of Winter eternal." - Patch 5.13
This is an update to to twisted treeline. They're saying that because of the third tower being there game times has gone up. This is true but it's not due to the fact the health of the first turret.
No, it's the fact that junglers can't really gank lanes all that well. The lanes are shorter than ever. You can't really punish someone when the lane is super short. People not dying = Towers not dying.