Unless Apple would make an anonymizing VPN connection mandatory, I don't see any difference to the situation as is. As long as people can be pressured to turn off the VPN, nobody loses any customers. Additionally, I don't think paying customers are the target, since they usually provide identifying information anyway.
If Apple started routing all iPhone/Mac traffic through some anonymizing VPN by default, services that block it would absolutely lose lots of customers.
Yes, but Apple wouldn't do this, because Apple is also at risk of losing customers when people get blocked by network security at work. We could also fantasize about Apple fighting all the tracking everywhere, including their own services...
Quite frankly, it's a bit silly to paint Apple as some privacy fortress, who wouldn't have to comply with law enforcement/intelligence to unmask/tap traffic. I mean, for a lot of people VPN choice is done considering legal jurisdictions somewhere far away. Apple could/would never possibly offer this level of protection.
It's a matter of numbers.
If 20% of people are using VPNs, blocking them is going to be a double-digit hit.
I don't think mandating that all traffic on Apple devices must be routed through their servers would be that great for privacy.