but without the ability to get/give support in close combat from/to other units. Something that infantry units need imo.
Making them cav based on the long side and that they can enter woods, would be inline with the fluff. The Ability to Attack flyers isn't a big thing imo. There are not many flyer units to begin with and with the new trial rules if cavalry hit flyers in the flank they can pursue flyers anyway. (and infantry attacking cav in the flanks can pursue cav)
When making centigors cavalry based on the long side they still can't get support from other units as they are cav but are more usefull to harras the enemy with their 30cm move. I don't see them winning any meaningfull close combat with 3 attacks, 3 hits and 6+ save at 80 pts charging them into (supported)infantry units will be suicide and easy victory points. Only 1 or 2 centigor stand can fight
when they would charge a unit in the flank
Just some thoughts

The rest of the beastmen list looks fine.