Rabbids official twitter (@rabbidsofficial) have confirmed that Mario+Rabbids Kingdom Battle will feature amiibo support.
In a reply to Edward Blangsted (@ed2ted14), Rabbids official twitter has this to say:
It supports the Nin Char Amiibo: Mario, Luigi, Yoshi &a Peach. Each unlocks a weap for the Nin char & it’s Rabbid counterpart.
The various Mario line amiibo will unlock new weapons for the individual character and their Rabbid counterpart. It is unsure at the moment if amiibo figures are the only way to attain the weapons.
— ? Barry Dunne ?? (@NinImpactGaming) July 20, 2017
Mario + Rabbids Kingdom Battle will launch for the Nintendo Switch on 29 August 2017.