While The New Yorker article tends to lump (as PeterJ points out) various flavors of non-monogamy, the central thesis--namely that consensual non-monogamy has become somewhat mainstream in Park Slope (Brooklyn) marriages and prestige (recognized production companies and production) TV --is on point.
The New Yorker is widely regarded as a bastion of literary reporting and of literature: the editorial process there is fierce. Authors need to be incisive and accurate, and they expect to be humbled by fact-checkers, editors, and copy-editors.
Two quotes jumped out at first reading:
"To some extent, art is catching up with life. Fifty-one per cent of adults younger than thirty told Pew Research, in 2023, that open marriage was “acceptable,” and twenty per cent of all Americans report experimenting with some form of non-monogamy. " and
"These shows, with their well-off couples ready to experiment with open relationships as a marital pick-me-up, depict the surprising fate of a radical social proposal. Non-monogamy, once the province of utopian communities like Oneida, which maligned matrimony as just another form of private ownership, is increasingly being presented not as a threat to bourgeois marriage but, rather, as a way to save the institution and all that it affords."