Spirit is a bad Nostradamus on timelines, when he is guessing, which he was. There is no serious indication that WDW's land is majorly sliding and I have seen nothing to suggest DL's can't be operational in the first half of 2019, if not the first quarter.
Clearly MF is keeping pace, so I'll propose a few other areas to watch for in the coming months:
1. By the second week of March 90% of the front side of Battle Escape should have its rock work steel up.
2. The land's large building supporting the semi-covered market should have about 75% of its steel and the archway over the entrance to the market street.
Finally, SW:GE in DHS would have to look worse than this for me to be seriously concerned it was becoming difficult to open it in 2019.