I believe it was supposed to be done in March already, when the refurbishment was announced. Looking at the daily schedule it will remain closed till September at least. Latest date we can check now is September 14th.
Apparently the front is ready, so the stage and seats, just not the backstage, but it was ok'ed to preform the show as is
But they also announced they'll broadcast the show in Cinemaque
It will be interesting to see how things turns out. Last time they were “late” for a new season was for the first year of Marvel, and it was a complete failure. Let's hope they get things right this time.
The rail road has been closed since October 2018 I believe. This is due to a mixture of cost savings and the construction of the new Frontierland Theatre.
They have actually pulled a section of the track up behind the new theatre to allow construction traffic to access the area. There were photos backstage from the run weekend which show the exterior of the back of the theatre wasn't finished in time for the Lion King show starting in June. Now the show has finished they will resume work on finishing the theatre, then replace the train tracks and then it will re-open.
It seems to keep getting pushed back - but it will be at least mid-December.