Polling numbers (actual gauge of public sentiment) show a net disapproval for Mangione: https://stratpolitics.org/2024/12/unitedhealthcare-poll/
If anything, the news media has been trying to push the Mangione debate and controversy at every chance, like the above article that was selectively written to highlight demographic groups that showed higher approval of Mangione first.
Thinking that “the establishment” is a collective of all major companies that act in unison is conspiratorial thinking. Don’t think for a second that the news media wouldn’t hesitate to push and profit from the controversy.