Not to go too far into speculation but your post gives me an idea which
I think would make sense with what Teebin is saying. Maybe a mine cart coaster themed to Donkey Kong, and another Mine cart one themed to Toad. The game that was recently released, Captain Toad treasure tracker, featured mine carts I believe. So maybe a DK coaster that is more thrilling, and one themed to toad and treasure finding that is more tame?
I think Skip has said in the past that we may be seeing a DK coaster, though things could obviously change. So I could see DK Coaster being something akin to BTMRR, and a toad mine cart ride being similar to 7 dwarves. Insiders can let me know if I'm hot or cold