I'm having trouble gaming this out.

I tagged Antpool on DedBird, asking "what? You guys don't like fees?"

The BcashSV empty block miner had a clear incentive: the fees didn't amount to anything worth the effort of including them. Winning the block reward made more sense at the exclusion of fees.

It could be just a natural technical goof. Part of the mining header scheme (article). Or there may be some political statement Antpool is trying to make. I'm not sure what the real answer is.

https://bitcoinmagazine.com/business/why-do-some-bitcoin-mining-pools-mine-empty-blocks-1468337739