That's a real problem, but I don't think it's related to this situation. We have to assume that censors can inspect apps, and can inspect some app traffic before it gets encrypted. This means that they'll know all about your servers and their IP addresses.
Push notifications? How do these work, when the app can't rely on access to any particular domain or IP? Your posts in this thread seem to include a great deal of hand-waving.
It was used by Akamai to do automated billing from the edges in the nineties when it was the first network that billed per byte delivered at the edges with multiple tiers.
It is very easy to kill an annoying mosquito in a room if it can hide in 3 places. It is much more difficult if it can hide in thousands.
Sure that could work for a while, even if it's a bit inconvenient for users. Eventually the bastards will filter emails too. Spam filters could certainly be trained to find these notifications.
