I think there are certainly some people like this, but only some.

I think there is these 2 things to consider:

Obviously this will change nothing for most people. Baseline, 99.9% people will not be doing anything different today than yesterday. I think the way Apple acts is ridiculous and outrageous, but I already thought that and already don't have an iphone. My wife doesn't even know who Epic is or anything about ios developers or 30% or any of that, and nothing is changing about her iphone. Nothing changes in either case.

But there will be some subset of current Apple customers who see these actions as exposing an attitude they don't want to reward, enough to stop being Apple customers. Maybe it's the latest thing that adds to the constant stream of other criticisms that they've always heard but have been just excusing or dismissing but eventually they see something they decide is "see enough smoke, maybe time to stop doubting there's a fire". It's not a large group but not zero either.

But will there ever be anyone that goes the other way? Is there any such thing as a current Android user who sees Apple do this, and specifically because of the way Apple treats developers, that convinces them to switch TO Apple? Well there's at least one of every imaginable freak out there but there certainly can't be a class of these.