There is little reason for a new audio format. Given that the current sound formats involve lossless multichannel sound, at a high enough resolution that it is essentially perfect for the number of channels supported, the only reason to add a new format would be for more channels. As things are, few people use all of the current ones, and don't have room for more.
Also, most people sit so far from their TVs that they don't even need 1080p, so 4k is already a total waste of money for most people. If they not only have to waste their money on resolution that they are not going to use, but will also have to replace their receivers, some of them will be more likely to do the sensible thing and just pass on it altogether.
That said, I have no idea if the makers of the new 4k have rocks for brains or not, so I have no idea if they will do anything sensible or not.
