Fairy
Offensive
SE>Dragon, Fighting, Dark
NVE>Steel, Poison, Psychic, Ice
X0> Grass
Defensive
SE>Steel, Poison, Normal
NVE>Fighting, Dark, Grass
X0>Dragon
Grass types mostly rely on status, so a resist won't affect them much. I'm also surprised with how many Fairy types and moves are centred around Grass types that there was no type match ups between them. Grass types are an unusual defensive type but a Fairy immunity would give them a nice edge.
Ice having another resist would hopefully bolster mono-Ice types up a bit, especially ones like Avalugg and Regice. Also based on how Fairies have a connection with plant-life, and many of their moves are based on embracing - both things that the frosty cold deters or kills.
Psychic having another resist helps as well, and would make Malamar not completely shit. They've been completely outclassed by Fairies so resisting their superiors feels fair to them after the years of the nerf-hammer. Also based on mental clarity seeing through the illusions and charms of Fairies.
Fairies is a fantastic defensive typing since Steel and Poison are ass offensive types, but Normal moves are often run for their good neutral coverage, as well as various mons running -ate abilities. A Normal weakness would stop Fairies from being a defensive king, an would make people think twice before getting their -ate Megas out in the face of a team with a Fairy. Also based on Normals being too "normal' to be affected by all the fanciful mystery and charm of Fairies - they're all Simple or Oblivious, in a way.
R8 'n' H8, M80s.
