There's two phases for cartridges on the way out:
Obsolescent means that nobody produces rifles for it anymore.
Obsolete means that nobody produces ammunition for it anymore.
The 222 is neither. Savage has two models of the 25 in it, Ruger has the No.1 Light Sporter. Midway carries 19 different loads by 9 different manufacturers.
Now it's definitely a legacy cartridge. The 223 pretty much took over its niche. But it's a long way from obsolete.