I can’t wait to see how they physically release the digital version.
But they didn’t with the digital versions so who knows?
They didn’t need to because George never signed away the digital distribution rights for the other five movies. That’s why there was no waiting game for the digital release.
You can’t get ANH on Disney’s digital download platform since they don’t own it, but you can on all the other services like google, amazon, itunes, etc.
They would need to broker a deal with Fox in order to include ANH in a hypothetical new boxset post-2020, but even if they can’t there’s a very simple solution: just release the movies individually.