Patreon doesn't lose anything to Apple - they give creators on Patreon a choice - charge Apple users more to cover the 30%, or eat the loss. I don't know what Patreon's take is, they are going to take the same either way. However they know their customers and users will lose from this and it is good for them to look out for their customers (it doesn't costs them much)
Patreon's take will not be the same. Apple's fee is charged first. So for all the creators that don't raise prices, Patreon is also getting 30% less, because they charge flat fees. And every creator that does raise prices will probably end up with fewer patrons, or patrons donating less, and will probably have a similar effect.
It also just kinda harshes everyone's vibe when they eventually realize they're being gypped and paying a lot more than others for the same thing, and that can cause people to just unsubscribe.
I believe Patreon's fees are a percentage of the total cost. i.e. if the payment is $10 and Patreon takes 10%, they'll still get $1, Apple get's $3, and the creator gets $6.
I'm not sure how Patreon will explain things to their creators, but no matter what the effect will be similar; about 30% less income for Patreon and creators alike.
According to App Store rules, you're not allowed to disclose the App Store fee to users. So Patreon is not allowed to explain to users that 30% is going to Apple, nor to explain that there are other options. I'm not sure if Apple regulates messaging to creators as well.
Customers leave when prices rise above their willingness to pay. Some customers will realize on their own that they can bypass Apple's fee by subscribing through the browser, but most won't (since Apple forbids even mentioning this trick).
Only if the users follow. If users decide they won't use the mobile web then patreon and the creators they represent lose. Nobody knows for sure, but there is a general belief that users will not follow (or at least enough won't follow).
Perhaps, although that requires experimenting the new fee model first.
It's too big of a decision to take without actual numbers, and having gone through it for a few months also helps on the communication side: on the surface Patreon at least gave it a try, and there's even a chance users are pissed off enough by the new model to campaign for that change and defend the move to their fans.
But patreon earns off of those purchases, right? And since a 30% price increase deincentivizes purchases for customers, they'll have less purchases.
Or, of course, eating the 30% fee yourself deincentivizes you to use the platform (or upload content as regularly) if you opt for that one
I'd say it's a loss for everyone involved except for Apple. Since Apple now gets a cut from all transactions its hard for me to see this as anything else except hostile and arrogant