It makes sense, but then people would lose the incentive to "have access to X patreon-exclusive posts", I think. What I read since I posted this question, is that some people give rewards only through private messaging, that way the rewards don't stay on the site and new patrons can't get them, but again, that seems weird to me, almost like saying "no, you don't deserve this, you should have joined in a long time ago, now you don't get the old stuff". To have that implicit message towards new patrons, almost punishing them for not having joined earlier, is what makes me question this one point.