I mean, it doesn't have to be a 1:1 spiritual successor to Diddy Kong Racing. Just like Yooka-Laylee, I expect a proper evolution of their vision of a fun racer. The only thing I would like to insist on is the three types of vehicles (karts, hovercrafts, planes) in some way and an adventure mode with an overworld. Everything else, like the controls (oh they better make the controls better

) and the gameplay can vary and evolve to whatever they like to. Oh, but the upgradable-item system was pretty genius as well.
Rareware/Playtonic were/are probably the only ones that can deliver an experience on the same or higher (high) level of a Mario Kart. And the DKR formula deserves a proper evolution. Who will do that, if not Playtonic? Who knows, maybe they even gain Nintendo's trust to directly do a DKR sequel with Nintendo / Playtonic characters instead of Banjo and Conker (whenever that will be, that is). I would love that.