No, don't give them any time, and don't be polite. Be vocally angry and cancel all subscriptions immediately. They NEED to know how bad of a change this is
I dont usually respond to anonymous messages, but im going to assume you're young and this is a learning opportunity, so let's go over a couple of things.
First let's go over the need to be polite when addressing the official channel's
The people that will likely have to read these messages probably definitely didn't have a say in any of this. Yes they probably have an AI sorting things, but we can still presume a person may see things at some point
Going back to the AI point above, or even without it, being verbally abusive about things, even if its justified, will quickly end up getting your complaint thrown out without consideration, making your time and effort worthless, this advice isn't just for a Tumblr protest, but alot of political ones as well. Start polite, you can always escalate from there.
Next let's adress the 2 weeks notice and the benefits of offering new business if they comply.
Canceling immediately may feel good in the moment, and quite frankly its not even the worst idea. But by giving them a reasonable grace period to roll back their bullshit its 1: giving us time to coordinate as a group 2: establishes clearer cause and effect 3: makes us seem more reasonablein the request and 4: on the hopeful chance of them capitulating to our request its less of a hassle to keep an already existing payment account then it is to cancel and refile
The offer of new business is even more important because if you only offer the stick ( retracting your funds over bad things) and no carrot ever ( paying them more when they do the things you want, even if its for less then Nobel reasons) then at some point businesses are going to start going with the mindset that there is no point in paying attention to when people start leaving as long as you can maintain a smaller loyal band of yes men that do like the bs
