I'm certain there are more than two. I've played the first game and they're rare, and you actually have to find them, but I think there's about five or so. You may not find all of them, but that doesn't mean they don't exist. The fact that the first game functions like this without the ability to purchase them screams intent, and that intent was not for it to be sold. That was something forced on them by the business side.

If you want to argue the limitation is only about selling them, you must explain the existence of the same mechanic in the first game.

Edit: It looks like both games have a hard limit of 10 at any time. Once you hit that cap there's no need for more. With this consideration, it really doesn't seem like a great way to try to force MTX to happen. If they really wanted to do that it would be a different item without a limit. The fact there's a limit means once you reach 10 any extra are wasted, and it appears that they may be purchasable in game in 2, and I'm confident you can find many as well.

Since when do we trust game journalists to get things right all of a sudden? Then saying they found 2 shouldn't be an indication of anything, other than them finding 2 and certainly missing more.