My take on Antpool isn't that they're deliberately excluding SegWit transactions, but they do seem to place greater emphasis on claiming the block reward at the expense of filling blocks.
Yep, that seems the case (I think I read it in one of your replies in another thread). However, the incentive manipulation is the same - they seem to use a special software to "bypass" the weight measure, which was introduced to reward Segwit-transaction users, and decided again taking into account the price per kB.
The good news is that there's an easy counter-measure every Bitcoin user can help with - continue to increase the usage of Segwit transactions, and avoiding services which do not offer them (according to the Reddit thread, some of them do this for ideological reasons, and considering that Segwit is active for more than a year now, I tend to agree). If this practice continues, I'll publish a list of "Segwit-boycotting services"
The more the Segwit percentage increases, the less Segwit transactions pools can discard if they are rational and don't want to lose money.