I wasn't into Whitney or Heather in season 1, but I think they've been totally necessary in season 2. Whitney for bringing the mess, and Heather as the Mother Hen of what's genuinely an insane group of women to have to translate into a cohesive TV show. She's not my favourite by any stretch, but Heather holding the centre snowflake feels totally right this season.
Heather coming back for season 2 was probably signed and sealed once it was revealed that Rihanna had DM'd her support to her. Andy lives for that shit.