Apple says the VP9 codec no longer works on Catalina. I want this codec for the older OS. Where can I find it

Apple has a page listing "Media formats affected by the transition to 64-bit technology":

In macOS versions up to and including macOS Mojave, third-party software has extended the QuickTime 7 framework to support many incompatible media formats. In macOS Catalina, the QuickTime 7 framework will no longer be available, so incompatible formats won't be supported in Final Cut Pro, Motion and Compressor.

Here are examples of media formats affected by this transition:

The second item on the list of affected formats reads:

AV1 / VP9

I am on an older version of macOS, and I would very much like to have native support for VP9 in QuickTime! Unfortunately, I am not aware of any QuickTime components that add compatibility with VP9. Perian, which is listed seperately, only ever supported up to VP8.

Was there ever a VP9 QuickTime Component, and if not, what is Apple's page referring to? I am looking for the name of the specific software being referenced.