Nobody can predict the future. My 2 cents is that ETC will fall further and further behind ETH as time goes by. Also adoption (see EEA) seems to be on the side of ETH.
Then there is the Grayscale/ Barry Silbert thing. To me it's obvious that thats an attempt to damage ETH vis a vis Bitcoin as opposed to real interest in ETC tech. Silbert was always against ETH (before the fork) and then all of a sudden was in favour of the tech. ETC fans will shout 'immutability' but I dont buy that.