It is unclear to me if this only impacts developer URLs (are those a different thing?), or if all user created short URLs will stop working too. If it's the latter, then a lot of links on the old web will break, and that will be so sad.
The developer focus is because Google has considered it a developer offering, but this applies to all goo.gl links, AFAICT; they explicitly say they are turning off the link serving function at that domain.
This is the latest announcement in question: https://developers.googleblog.com/en/google-url-shortener-li...
In 2018 they said goo.gl links won't stop working: https://www.searchenginejournal.com/goo-gl/246569/