That's what I thought, too, but since it doesn't allow the box link option, as I said earlier it makes me suspicious about even sharing hyperlinks. It's for news, I guess, not sharing.
Also - as I mentioned, it would be on my profile. I could also put it on the pub page but it would be on mine, too. So if I'm sharing a bunch of naughty hyperlinks, I might still get in trouble.
Medium's non-transparency doesn't help. We can only guess and speculate and live in fear of doing something wrong! (Okay, I'm not living in fear but I trust you take my point).
It's actually about the same amount of effort for people to follow me on Patreon. They just have to give an email address, and then when I post, I can choose which audience sees it. I could just do 'free members only' for these, and they'd get an email, which is what they'd get if they signed up for a Medium pub newsletter. It's no different to them, but it means I'm absolutely safe in sharing the links on Patreon.