Large development seems unlikely 

While it is certainly possible that Disney could be looking to eventually develop this land as resort, transportation, backstage, or even attraction space, if those plans were coming together previously, given the current economic situation, we'd guess any major development is on hold indefinitely. Right now Disney doesn't really "need" any extra space for its projects, and with the budget being tightened by the COVID-19 Pandemic, there's no way that Disney develops this land in any meaningful way any time soon. 

However, several years down the road that could change, especially as Universal is developing additional parks, hotels, and more down the road, and Disney may find themselves wanting to compete more with their next door neighbor. But any such development would be MANY years down the road, possibly not even until the next decade. 

Of course, right now Disney has no comment on their purchase of this land, and there's no telling when (or if) they will announce their plans for this undeveloped area. But of course we'll keep our ears to the ground and as soon as we hear any developments, we'll let you know!