According to comprehensive rule 300.1 (page 56 of the linked pdf), the card types are: “artifact, conspiracy, creature, dungeon, enchantment, instant, land, phenomenon, plane, planeswalker, scheme, sorcery, tribal, and vanguard.”
Notably, battle is missing from that list. Probably just an error, but does this have implications for tournament play?
Can we think of any funny interactions because of this?
It looks like they forgot to update one of the rules, but remembered the other. Regardless, the card rules text always takes precedence over the comprehensive rules (not the reminder text though, anything in italics is not rules text), and rules have been created for how battles work, so they should function as usual I’d imagine.