Of the threads you’ve listed, one deals with app entitlements to call the addPlan API, which is nice to have so a carrier app can directly provision an eSIM, but not needed for eSIM provisioning via QR code. For the other two threads, it’s the same person both times making the assertion Apple’s eSIM is proprietary, with all comments being 3 years olds and discussing a beta iOS version.

So would take all of those sources with a large pinch of salt. If Apples eSIMs we’re proprietary, I would expect to be easy to find articles discussing the fact, given they’ve been around for a few years now.