They can and do say "All apps that do X are forbidden" while not taking down some apps that clearly do X.
None of this really matters though because the title/claim are still bogus.
Apple does not move quickly, or consistently, or sanely. The continued presence of the official Pebble app on the store is completely consistent with a new Apple policy of prohibiting apps that talk about Pebble. Apple often starts by simply rejecting updates, and the Pebble app hasn't been updated since February. When Apple does start going after existing app versions, it often takes weeks or months. For example, there were several stories from the past fall about apps that came up with novel uses for the new Today screen in iOS 8, submitted, got accepted, were in the store for a month or two, then were suddenly given the choice of removing the feature or being yanked because it turns out that they were going against the arbitrary rules about what you're allowed to do in a Today widget.
What matters is that some dev made a wild claim that Apple is actively denying Pebble apps for being Pebble apps, when in fact they just failed to follow the rules. That's all there is to this. That this story is as popular as it is is ridiculous. The headline is clickbaity as hell and just outright false.