Zyra needs a big buff or two. For having some of the highest mana costs in the game, having some of the easiest to dodge skillshots, a trashy passive, and a buggy plant AI, yeah I could see some buffs given to Zyra.
She is a meh Support and a mediocre Mid Laner. She's outclassed by pretty much every champion. If you want a poke Support with CC? Pick Nami. If you want a zone control minion mancer? Pick Azir or Heimerdinger.
I think in the case Riot does buff her they should NOT buff her damage. She does plenty of damage. Though that doesn't justify picking her.