As soon as browser support the standard, the message will be shown less and less. Chrome was an early adopter, but Audio Worklets are part of a W3C working draft, which is the de facto standard for web audio:
However, I didn't refer to "browsers that don't follow an early adopter in implementing a working draft" as "old", though; if you read the compatibility message carefully, you'll find I referred to them as "unsupported" (which might be a bit inexact but not disparaging).
Non-evergreen browsers, instead, are correctly referred to as "old", because they are.
> Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.