Say you were to buy a tier, you'd then have access to all the previous stuff right? Or is it set up in a way to where they can literally do a monthly thing and it's only accessible to the people that had that tier prior?
Judging by the one's I have joined in the past the ones that post directly to patreon their stuff is always available after posting. BUT many are posting content to a third party site like google drive. vimeo and dropbox then sending links to the members. so you may want to ask how you will get content before pledging.