Sort answer? Yes.
Certain damage access is putting specific champs like teemo over the precipice of being countered/counterplayed.
We didn't have a Rune/Mastery before that dealt significant damage on the first hit of a skill like Aery or Comet, and nothing actually synergized with Teemo's shrooms before. He was already low cooldown, and now his cooldown is even lower (It's also very hard to counter heimerdinger for much the same reason). He has more access to move speed as well, all while no skills/items were adjusted. Teemo didn't used to finish fights in one Q and one auto attack. Now he can and does. Even if those 2 things don't kill his target, the damage is enough to force a retreat, which is in itself a win.
Certain assassins are more dangerous and when played right also have no counterplay. Duskblade is simply broken, and we now actually have champs building 3 non base stat ways to chunk damage (Duskblade, Dark Harvest, and Muramana are all on hit procs to basic attacks, so any champ that can hit "unseen" can use 2 or three of them (Ezreal can use all 3, Kha can use two, Rengar can use two, etc)
They also put in a ton of recovery options without considering how they stack on champs that already have crazy self sustain. Garen even when unfed can now sustain enough to heal out of 95% of fights, even 1v5's because he both has the 60% tenacity + and the life regen and the life on damage taken, and the recovery from damage done to just mow through it. Mundo can go full tank and 1v5 because his regen also is not considered when balancing all these new healing mechanisms. Even Leona now can reliably heal (some games I have readouts of actually having over 16,000 heals on Leona, and that's coming purely from runes).