I've read that article as well, and I understand in a perfect world it would.
My question is, in a majority of situations, it seems as though students are encouraged to send "love letters" to their #1 program, with the implied consideration that if a program does not receive a love letter from you then they will strongly consider you unlikely to attend their program if offered an opportunity. As a result of the fact that programs all want to match their top applicants, this makes sense to me.
So in a world where the programs know the students match list, and PDs talk so you cannot send multiple love letters, it seems as though students are put between a rock and a hard place.
Either don't send a love letter and possibly don't get ranked very highly, send multiple love letters and risk pissing off your top lets say 3 programs, send one love letter and possibly go unmatched because again the program flat out lied to you about their impression of you and your ability to match there.
What is the "optimal" solution here?
Take the following with a grain of salt because the match culture among specialties greatly differs.
I agree, it's very tough for the applicant. I've had many similar discussions with co-applicants in the recent past about this, and we have come to the conclusion that there is no optimal solution in the current culture of the match and post-interview communications. You're absolutely right, there are programs out there that want you to send love letters so that they know they are ranking people who are in turn ranking them #1...but those are programs that generally have a reputation of advertising that they matched their "top X for the past decade" or something along those lines.
That being said, the vast majority of programs out there have no vested interest in advertising such a thing, and play by the rules: meaning they will rank who they like and let the chips fall as they may. Like @operaman said, there are also a lot of programs who rank immediately after the interview and have an internal rule of not changing the rank lists afterwards...so love letters and phone calls mean nothing.
Something that my particular specialty has done to try to stem the tide of this post-interview communication shenanigans is ban post-interview communications all-together between an applicant and a program. Even thank you letters are considered taboo. Though I'm sure attendings talk to other attendings, I think this has worked quite well in forcing people to play by the rules and letting the match work as it should.
Edit: so what should you do? So if your specialty allows love letters, send it to your top #1 place and be honest. Don't send a love letter to your top 5 places because like you said, PDs
DO talk to each other. I've heard stories of applicants telling multiple places they were their #1 and PDs found out from each other. Needless to say, this did not help him/her in the match process. Programs understand that they won't match their top 1,2,3, etc in a row. It's not how it's supposed to work, and rarely ever works that way. Just because you didn't send them a love letter doesn't mean they won't like you or rank you highly...and just because you weren't ranked #1, 2, or 3 at a program doesn't mean you won't match there. I guarantee that the majority of applicants ranked to match at programs were applicants that did not send love letters, and were ranked that way because of their overall package, social skills, and how they carried themselves during the interview.