Bad idea for the FCC to demand it.
(similar bad intentions by the government haven't stopped the conversion from analog to digital broadcast TV, without compensating broadcasters or viewers that have to pay for what amounts to another "unfunded mandate".)
If one looks at the total number of analog satellite signals left,
the marketplace will take care of the problem. Most channels have already converted to, and/or are simulcasting in digital. When you can get 10 digital channels or more into the space of one analog, economics for the uplinker make the decision. The FCC should not be "demanding" anything....as this "problem", if there is one, will fix itself naturally in due course. There is presently a surplus of satellite spectrum not being used, even with many dozens of analog channels still up there. The marketplace will sort it out as it always does!