I have a lot of experience with SV, so I can actually answer definitely. The AP Control Panel is not at all required for AP on SkyView. It's only role is to make AP easier to operate. (It's not hard from the panel, but dedicated knobs and buttons are obviously handy in IFR.) The AP Control Panel is not required, though, and is NOT currently part of the STC. I asked at SnF, and autopilot is definitely part of the current STC and planned for future models (e.g. Mooney). They hope to add the AP Control Panel, too, but can't promise anything there.
As for timeline for Mooney, their rep had 2 comments beyond what @Maurader already said: 1. They recognize that people are more likely to invest in a panel upgrade with a larger hull value, so Mooney and Bonanza could none ahead of, for example, Pipers, and 2. They recognize that if the upgrade isn't possible before 2020, it's appeal and value drops.
Hope that helps!
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