My guess on the writer of the NYTimes Op Ed is that it is someone who is very much a movement member, thinking long term, concerned about the election and as worried as much about the long term conservative movement as the health of the country.
So who has those connections and interests? Two — Bill Shine (ex Fox News head, now Director of Communications, very tight still with Rupert Murdoch). And Kellyanne Conway, who is the Mercers’ creation. The latter (and possibly the former) has lots of contact with the NYTimes, feels safe in trusting them (suggests often done anonymous sourcing with them). Shine is NY media inner circle; Conway if she did it likely cleared it with the Mercers.
I’ve always felt that Trump will go only when the right wing powers — Mercers, Kochs, Murdochs, NRA, religious right — at least some of them regard him as a liability. This is what could be starting to happen.
It to me feels logical that Shine or Conway would be the one. Conway has been there longer, observed more, so my bet is on her.