I read that as:

we need to re-work the collision detection because it's bugged, since we will be getting our hands dirty under that hood anyway I want to add in environmental interactions like mantling (animated climbing up/over ledges) and crawling up/sliding down minor hills .... and since all that will require major editing of the games environment we might as well redesign the environmental visuals and map layouts as we feel like.

I wouldn't expect something major like being able to climb the trees in Grid, and are still gonna be seeing a lot of the same geography over and over again, but we can probably expect a few additional set pieces mixed in and a better recombination of things to be less monotonous.