I would expect that if the new satellite takes a ka slot "around" 101, in addition to the current 101, they could design a new lnb that does 99, 101, 103 with ka/ku on 101.
It would be very similiar to what Dish is doing with the Dish Plus - 119 and 118.75. Just add in the extra two sats at 99 and 103. Complex, yes, effective, absolutely.
Essentially, they could go with 6 lnb dish, same size as the au9, or could drop to just 4 lnb using 99/101/103 and go with a slightly smaller dish, or just use the same as they have now.
Either way, it is all in the LNB and where they put D12.
Remember - by then SWM will be ready too, hopefully it will all be rolled into one.