if anyone is willing to take serious action, they can sue patreon for fraud for allowing a scam of such magnitude to happen on their platform. there is a pretty decent case to be made as fraud is defined as using a lie, deception, falsehood, or dishonesty in an attempt to gain a benefit. which is clearly what icstor has done.
The screenshots from icstor's patreon's posts where he makes multiple promises regarding communication or updates or whatever else he can come up with, even using patreon themselves as a scapegoat in the most recent instance can be used as proof. He has displayed a pattern of repeatedly making false promises. To finish off, an argument can be made that he is not an honourable or ethical person by pointing out the fact that he did not create anything for more than a year and yet continued to take money from supporters. he had the option to disable payments just as he did when he announced that he was taking a break (after the caroline update) albeit he lied even then as he said he would pause if for 2 months, the duration of his break, but in the end, he paused if only for one (correct me if I'm wrong). he didn't need to communicate anything as long as he took wasn't taking their money. but without any communication, he led his supporters to believe that for a long time development was under progress. then a point can be made regarding the size of the updates and how after almost 2 years of "alleged" development there is only 400 or so renders while previous versions were far larger in much shorter times.
patreon can argue that it's the supporters choice to follow a creator, the counter-argument would be that it's not about the choice of the supporter and more regarding the fraudulent creator who has been allowed to continuously lie on their platform and that patreon isn't taking much action to protect their customers. and neither do they have the provision to report such a scammer. that patreon is just turning a blind eye to such bad and somewhat illegal practices.
It has been almost 23 months since 14th Oct 2019 (the release of 0.6c), excluding at most 2 months for 0.71 and 1 more when he paused his patreon, let's just say 2 for argument's sake, each month he has taken money from the support of 5500 people on average. and with the game being accessible to only those who pay 10$ or higher, the number of people paying more than 10$ from those 5500 is pretty significant. assuming that just 10% of the 5500 were paying 10$ or higher it would come out to 10450$ a month (550x10=5500+4950=10450). this would bring the total amount for the 19 months to 198,550$.
Even with such a low estimate, the total amount of his scam is pretty damn high. In reality, the average per patreon support was last calculated at 8-9$ on graphtreon. even if it dipped to 6$ on average, it would mean he earned 33,000$ on average each month. and for 19 months it would be 627,000$. for 8$ it's 836,000 and at 9$ it's 940,500. almost 1 million dollars.
Patreon will not be able to simply brush this under the carpet if someone does really take it up in court. This would definitely shake up the creators with massive followings that take their supports for granted and would really evoke a reaction.
The least this would do is light a fire under patreon's ass and get them to take action against icstor.