You said they are just saying it’s poor sales, but it actually isn’t the reason. That would make their posted reason a lie.
If marketing is not based in reality, yes, it is lying, and there is nothing toxic about calling it what it is. There is plenty of dishonest marketing out there, and some of it is even legal. But I would hardly call a discontinuation announcement “marketing” since you’re literally doing the opposite of trying to sell them the product. You’re telling them they can no longer buy the product.