Numerous people have been removed from popular social media platforms, and I've yet to see any of them make a comeback, let alone go up against Twitter/YT/FB etc.
It is unlikely we will ever even hear about Stripe openly leveraging their influence. They will talk to Substack, who will bring the issue to their investors, who will tell Substack that Stripe is higher up in the food chain than the writers.
These are names with a following and they have strong incentive to stick together if anyone on Substack is threatened with financial cancellation.