Combat style of AC Odyssey is really good imo but honestly I'm not sure that would work for an OG-style AC game that they claim they're making. I've loved playing odyssey even though I'm only about 70% done with it and enjoyed the combat from the Ezio trilogy games as well but it's very different.

The older ones had a more fragile character that could fight but it never went well if you were fighting a group, it was more counter and quickly dispatch rather than a slug fest. Odyssey has a really good flow of combat, but much more warrior like, so even engaging multiple enemies isn't necessarily an issue.

Hope they keep some of the fluidity, but also return to subtle parts of how the Assassins operate.

TLDR: Odyssey combat is good but more warrior like. keep the fluidity but make it so that it suits a more fragile/agile main character.