I wasn't really clear about the exact question...some possibilities:
1. Given the EDA gaming happening on the bitcoin cash chain right now, the bcash chain may have its next halving in 6-9 months (or less).  And could have another one a year or less later IF the gaming continues.  Is the question whether at that point the fees per block on BTC plus the mining reward will be so much greater than the BCH chain that the gaming would have to stop?

2. Or is the question whether after the next Bitcoin halving the fees per block will be larger than the block reward (or close enough to it) and so a fork would be uneconomical because the economic activity will remain on the main chain so the combination of fees and block rewards would be sufficient incentive to mine only the main chain?

Personally I think either way the fees, particularly if segwit doubles or triples volume while decreasing average fees while increasing overall fees per block, will be a big incentive to stay on the main chain. Likewise, once BCH has a fast halving next year, the arbitrage opportunity will decrease and without the economic activity the chain's value will drop.  That is the problem with the bcash EDA, it is gamable making the chain less stable than one would hope.