I can't imagine the professional reputational damage I'd incur if I were to recommended wordpress, or worse, wordpress.com after all of this.

Genuinely, why? What kind of visions of reputational damage does having your marketing website on wordpress.com conjure up to you?

How would anyone even know where it’s hosted?

I get the guy pissed off some php devs but I’m sure as hell not hosting that shit myself, marketing team content can be their problem.

Matt cut off wpengine and could cut off any other commercial hoster tomorrow if he wished to do so. Why would you risk that?