The guy was just being honest.
Yes, he was already paid for the Xbox gamepass release. That doesn't change the fact that you are not giving him any money by playing on Gamepass. Both can be, and is, true.
He was asked what would be the best way to support his game, and he replied honestly. He offered the option that would get him the most new funds that he doesn't already get. What is there to be confused about?
The whole point is that Gamepass disconnects the gamer from the classic commercial reward of giving developers money for titles they like. A gamepass gamer just pay the monthly bill and unless they buy micro-transactions, have no real way to reward a developer. Their payment is just sent to Microsoft. This is similar to how you couldn't support your favorite show on Netflix, causing Netflix to kill otherwise popular shows after 2 or 3 seasons.
Consumer's greatest tool is our wallets. How we send our money determine what gets made and what we could buy. Spending money isn't a flaw, it is a feature. Money is how we vote for our favorite franchises. If Bayonetta sold more it would never have been forced to become a Nintendo exclusive.