You opened a duplicate issue as I have pointed out on GitHub.
Currently the internal templates can be overridden in individual projects, the forum has posts about overriding internal tempates, please use the forum search functionality.
Which theme are you using?
To answer your question:
Yes. The theme author should provide an update to that code. Not the Hugo maintainer.
Especially since the status of the internal templates for 3rd party services is currently under review and may be removed from Hugo in a coming release (see: https://github.com/gohugoio/hugo/issues/7893).
Hugo provides the internal template for injecting google analytics.js script i.e. _internal/google_analytics_async.html. Most of the Hugo themes use the same internal template to enable google analytics.
What you can do is write your own partial and replace that with internal template. Here is step by step guide:-