Google updates its algorithms all the time and the MUM update, which was rolled out back in June 2021, focuses on how content in different languages is served, rather than how it’s identified and categorised.
MUM understands 75 languages and, essentially, will serve users with content that is most relevant/useful to their query, no matter what language the content was originally in.
So, in answer to this question, no. As an SEO tool and to help Google and other search engines understand the context and audience of your content, hreflang tags are still critical.