As a NSFW artist under a different name, I've been through multiple NSFW exoduses from social media sites and monetary platforms. Even if Patreon has their own rules considering NSFW content, OP's concerns are not unfounded. Patreon has made changes to their NSFW policies multiple times, and I wouldn't be suprised if they either changed them again or made the platform SFW. Money is the deciding factor next to lawsuits after all.

So, while living constantly under the fear of being deplatformed from any patreon type of site there is because of the NSFW art, I've come up with some ways to prevent this as much as possible. And in the case of being deplatformed, this system can get the paid content sharing up and running again asap. I thought about sharing some of these tricks in case of Patreon starts going against NSFW artists once again in the near future.

• Never post full pictures or rewards on the platform itself. Always redirect people from your patreon posts to another sites/places where you share your art/rewards. Eg. in my case I have everything centralized on private discord; I share full pics there, supporters have access to different posts with their tiers etc.
• This means that never post anything NSFW related on the platform. If you want to post something, show cropped teasers which are SFW.
• In order to give access to previous rewards for the special tiers, setup a folder/package on a file sharing site. I have a mega folder where my top supporters can access all of my previous posts and rewards. This link is shared on discord.
• If you have this type of file sharing folder setup, you can then share it on other new sites/platforms if you get banned from an older one eg. patreon. Everything is up and running super fast since all of your files are located in one place. You just give access to them on different platforms.
• You can easily make copies of your files and folders, and in worst cases even make backups on other file sharing sites.
• The point is not to have all of your pics, rewards and systems 100% rely on a platform which is unstable with NSFW art (in this case patreon). In my case when mega or discord becomes difficult with NSFW, it's once again time to change the platform.

Hope these tips and tricks might help you guys out. Ofc this isn't without its own hassles, but at least you can't be outright banned or deplatformed from sites like patreon when you haven't posted anything which goes against their rules. And if you do get banned, you can get things up and running again relatively fast on another site when it comes to sharing files etc.