cr2032 are lithium, but not usually the same chemistry as rechargeable lithium ion. (side note, some cr2032 cells for use as battery backup for realtime clocks are actually rechargeable, which is pretty cool) However, as the sibling comment says, they are allowed because there is a threshold below which batteries are allowed.

a cr2032 is an example of a "lithium primary cell" meaning it's not rechargable, whereas "lithium ion" is rechargeable https://www.mpoweruk.com/lithiumP.htm