That is an invalid association, just because someone stops you from doing something ('artistic'?) doesn't automatically make it censorship.
eg.
If a home owner stops me from painting the side of their house in an artistic manor (without their permission), are they censoring me?
What about if the relevant people stop me from holding an impromptu and loud rock concert in my local park at 3am, is that censorship?
Or if the local furniture store stops me & some friends from have a long discussion while sitting down on the store's floor stock, would that be considered being censored?
The developer has no intrinsic rights to be able to access Patreon's services, and the develop is still able to create whatever they want just not on Patreon.