It would be deeply frustrating if Yubico were to spend years coming up with a 2FA product that works with iDevices, and then a few months later Apple were to throw out the interface that product depends on and thus instantly make it completely obsolete.

(One would hope that Yubico and Apple have been in touch with each other at least the minimal amount that would be required to avoid such a fiasco. But given Apple's penchant for secrecy, who knows?)

Current iPhones will at least be commonly in circulation for a few years, so it wouldn't be a complete waste.

It would be a classic Apple move to do that, though, further reinforcing the codependent relationship vendors have had with Apple for decades.