I've read that before, and I don't believe Ohmori. Sakurai left a spot open for an X/Y Pokemon before he even knew about any of them, when there were literally hundreds of existing choices, with at least a sizeable handful that Sakurai could undoubtably have "shown off in a really cool way", without having to jumble development by leaving placeholders in the project plan, which clearly isn't his typical MO.
When Sakurai talked about Incineroar, he said it came down to it and Decidueye. Why just those two? Again, there are hundreds of choices - isn't it a bit coincidental that they just happen to be the exact kind of Pokemon that'd get pushed for promotional purposes?
Plus, if Sakurai narrowed it down to those two because he was genuinely interested in them, and he calls the shots, then logically we should expect Decidueye to still show up at some point. But we all know that's not going to happen. Because for some reason, Sakurai always seems to pick from the newest gen, doesn't he?
Pokemon are clearly chosen with a promotional slant. And that almost certainly doesn't come from Sakurai, because why would it? That statement is PR talk. Or, Ohmori is leaving out the part where they first present him with the acceptable options, then he returns with his ideas, at which point they defer to him.