No, I mean literally changing types so that you keep neither of your pre-evo types.If you're counting changing the primary type but keeping the pre-evo's single type somewhere, Ursaring -> Ursaluna already pulls off Normal to Ground/Normal.
There's also Goomy -> Sliggoo-H going Dragon to Steel/Dragon (that much iron in the water?!?), Slowpoke-G going Psychic to Poison/Psychic whenever it evolves, and Gimmighoul -> Gholdengo going Ghost to Steel/Ghost.
On a somewhat similar change-primary-type note, there's Mime Jr. -> Mr. Mime-G going Psychic/Fairy to Ice/Psychic.
Swapping order is whatever, they never had any meaning for what I care. I mean actual full on type change (like A-Marowak going from Ground to Fire/Ghost).
Outside of Eevee, A-wak, and maybe 1 or 2 I may have forgot, every pokemon keeps at least 1 of its pre-evo types on evolution.