For those of you that haven't seen, Riot has major changes for next season that include an apparent buff to many stealth champions. If this change goes through, Vision (pink) wards will no longer be able to reveal champions who are able to use stealth that labels as "Invisibility" (NOTE: This is mostly for in-combat stealth mechanics, so champions like evelynn and rengar will not be able to hide from Pink Wards), some examples of champions affected include Leblanc's passive, Vayne ult + Q combo, and Akali shroud (W).
Riot's logic behind this is that Pink Wards are very cheap and are a hindrance to certain champions being viable in higher levels of play, I can understand that but this change also takes away a lot of counterplay for the people fighting against them. Typically if you wanted to 1v1 a Vayne or Akali you would bring a pink ward so that you could counter their stealth mechanic, otherwise they would just destroy you in the battle.
I don't know if this is the right way to go about balancing stealth champions but i want to hear what people have to say about this below. If this change goes through I expect Lee Sin to be picked a lot more since his e can reveal invisible targets (Unless this gets changed too).
EDIT: Source where the change is noted in-detail