And I don't want to downplay the innovative additions Apple made to the whole thing (browser integration etc.), but it doesn't make an honest impression if you don't mention that your revolutionary product is a based on a well-known standard.
Really curious for the reason behind that. If they would've mentioned it there probably would have been quite a bit less of lock-in criticism for the product. But maybe they are also banking on the devs not realizing that they aren't that locked in and have an easy option to move away.
The main requirement therein I would say is that you can't use OpenID to describe an implementation unless it implements the mandatory-to-implement parts of the relevant protocol specification (and all the specifications are 100% free; e.g. https://openid.net/specs/openid-connect-core-1_0.html ). That's more about interoperability than anything else.
So I asked my friend if he knew about these other companies, again all very well known in the specific market for AR developer tools, and he said he didn't and they don't actively look for companies they might be impacting when making product decisions.