If they go with the classic approach, I'd want something that takes inspiration from Rondo of Blood, which I consider to be the best of the bunch and near the top of CV in general.
But to be honest I would prefer a continuation of the 3D series, using the PS2 games as a template. Lament and CoD were good games with their own distinct atmosphere.
I would not have a problem with more Metroidvania but mainly if they skipped the part where devs start with a safe reboot before trying interesting stuff. It's a saturated market and if they go this way they should try something weird right off the bat.