I wish I knew.
What I have been doing is checking periodically. When I initially went to file, TurboTax was requiring a date of April 15 or earlier. Trying again just now, it will let me use May 17 or earlier.
So the necessary change for the later deadline for all states (because of COVID-19) has now been put in place.
But still no option for June 15 for those of us in Texas. 😕
