It's not DIRT's job to settle the issue or even comment on it. Even if they know something, they couldn't and shouldn't say anything until there is an official announcement.
I don't think anyone technical ever had any question that a single Dish could feed both systems. The mechanics of a mixed system are pretty straitforward, and the install docs posted showed no real surprise. There are scenarios with multiple accounts fed off one Dish, so the docs show how to handle it.
The reports have always been that Dish won't allow mixed accounts and the billing system won't support it. The billing system can support whatever Dish wants it to, so this is a business decision probably intended to streamline install, support and billing, not a technical one.
It may be a permanent decision. It may be transitional so they can get the system out the door. It may be something they come back to and reconsider.
One thing Dish should not do is suggest even in the slightest, most non-commital way that they will support a mixed setup until they are sure they will follow through.