Not likely that they will join as I'm sure they have their hands full. And to be honest I doubt they'll even accept the challenge. But someone will tell them that they were mentioned in here and that will get their attention. They'll think about it, if only for a second.
That said, I picked them because from what I've seen, they seem to be the three people who are most interested in improving the platform. I say that because they are the most vocal about their beliefs. Well, GC and BS at least. Ned is the CEO, so it goes without saying. And by "challenging" them, I give them the opportunity to speak their mind under the guise of responding to me.
Less risk for them because they don't have to say, "this is what I believe and I felt like posting it just because." Nope, just because someone challenged them.
The guidelines I set up will hopefully lead to quality posts, something this platform could use more of. Any platform, really. But if they play along, then it's likely that other people would play along as well. That means a higher standard for posts on here and an increase in the perceived quality of the platform, which is ostensibly something they all want.