You probably already have this knowledge but just in case, it's always a good idea to check Curseforge, as lot of mod creators are posting their newly free content to Curseforge while keeping mods locked on Patreon. That being said, I've found that most creators follow the rules regarding release of mods in a timely manner, but absolutely there are some who look for loopholes in hopes of gaining additional $$ when some people get desperate to use inaccessible mods. Creators who use such tactics need to realize it is breaking the rules and unfortunately, paying patreons having unrestricted access are likely unaware of this and continue to provide support when they otherwise might not under such circumstances...some people have morals. If I were to start using a creator's content and liked it enough to think I might support the creator, but I see such behavior, it's enough to keep me from doing so. In the long run, whatever success they think they have, it's less than it could be using such an approach