Which, looking at the replies, is a mistake, because everyone projects the least charitable interpretation and/or assumes the article is dog-whistling.
The problem is that there are heresies and heresies, and conflating everything together isn't helpful.
To give one extreme of a "heresy": It's reasonable to not want to associate with someone if they're (in your perspective) ideologically reprehensible. In that sense, it was a bit aberrant that in the past most people would look the other way at stuff like racism and antisemitism in academia or the workplace ("none of my business," "not related to their professional skills," etc.)
But when other people think of "heresies" they might be talking about approving of a right-wing policy in a left-wing environment, or (moreso in the past) being labelled "communist," or taking contrary stances on things like wage equality.
So to reiterate my point, the article is flawed and can only lead to noisy nuance-less arguments until it spends more time defining "heresy."