Patreon should have a system where the developer sets a release date for each update and money stops on that date until the update is released.
Patrons can then decide if they are happy to give money to a dev based on those dates.
If devs want to set for example 12 months for an update so as to not risk the money stopping they have to deal with Patrons knowing they are doing that.
I really think that you and alot of others who are overly concerned with release dates and their correlation to patron donations are confused about what being a patron means.
You are NOT paying for content, at all. You are donating, I. This case on an automatically recurring monthly basis, to an artist be cause you like their art and their process. This has been the case historically with artists and kings/rulers/wealthy people. This is also the case now. You, as the patron, are SUPPORTING THE ARTIST. Period.
You are not contracting for specific pieces of art, that is a commission. You can remove your support of the artist if you feel compelled to do so, but don't treat the situation. As though the artist owes you anything. They dont. And vice versa, you owe the artist nothing.
Please SOMEONE tell me they understand this dynamic!