cause enough friction that enterprises will start looking to other distros

Highly unlikely IMO, unless someone else enters the market of commercial support.

I’ve been working for big enterprises for decades, not IT companies but big nonetheless.

The reason why Linux could “break the barrier” and enter the enterprise market (at least in EU) is that one day Red Hat became a company capable of guarantee support by means of support contracts.

Big enterprises don’t care a product is the best in the world IF they cannot have a contract with some entity capable of commercially supporting it every time there’s a problem.

I believe it’s very stupid on IBM part to make this move, but as long as they maintain their contracts, big enterprises will stay on Red Hat, they won’t care about what will happen to independent developers, they wouldn’t be using their software anyway.

Very sad, but at enterprise level there are not many choices when it comes to opensource software.