Hopefully it was a mistake and Fukunaga was talking about bringing over the OVAs, since it seems like the staff are still interested in animating more content. It would be interesting if they adapt the second half of the manga and we get to see the parts we missed like Kanou's lab and V14, but I otherwise don't see a point in another season. It would be weird to adapt :RE because Root A was precisely a different route and it would feel half-baked to tie them together. That, and it seems too late to try and adapt Ishida's Root A storyboards more closely a second time. Overall though this is just information I wish we didn't get until there was an official statement