These situations are always included in the program just not explicitly.
The key question is, did you change your domicile? Your domicile is your permanent home. It is where your significant family, cultural and legal ties are, like your church, doctor, dentist, and so on. If you did not change your domicile, then you are working temporarily away from home and you owe a non-resident tax return to the state you are temporarily living in and a resident return to the state of your permanent domicile. You get a tax credit on the resident return so that your total state tax bill won't be higher than whichever state as the higher rate.
If you actually changed your permanent domicile -- you moved permanently, and won't be returning to your previous state even after the pandemic is over, then you just moved, and that is already covered in the program.
I agree that guidance on this would be useful.
