You are right. Perhaps NE region has minimum number of subscribers, and perhaps many will not be even aware of this addition. If 20 plus tamil channels are made mpeg4, one transponder will be released with a capacity to add another 25 new channels. Even the new channel pudumugam which is to be lunched soon will in mpeg4.
TS can easily do an analysis and decide which language/ subscriber base is to be targeted for progressive change over. Anyway cost stb was borne by the customer; tS could have supplied mpeg4 stb from the second or third year.