[dralley]

> It might not matter much if Canonical or IBM decided to port a critical mass of open source extensions/packages. Then they could ship the new CPython in place of the old one and mention the differences in the release notes.

The lifeblood of Canonical and Red Hat / IBM is long term platform support for companies that want their most critical code to not break underneath them.

Even if the open source libraries get ported, there are still plenty of proprietary C extensions out there for which this would be a breaking change - the "dark matter" referred to in this post.

It would make zero sense for them to "throw their weight around" and _unilaterally_ break their customers' code if even the upstream devs didn't want to go through with the changes.