I present an alternate theory.
If you've not read it yet, you may want to give my post about electoral reform a read. You'll note that almost all of the reform proposals would see a new "Reform Party" springing up. My earlier examination of "Urban PR" could even be the best possible system for such a party; which would lock up wins in the rural areas, while getting a few seats in urban areas where they would otherwise win nothing. This becomes far more likely if the rural ridings accept a form of ranked ballot, something that may not be possible if the proposal is to get Conservative support.
Kellie Leitch is one of those people I've had my eye on for a while as a political watcher; she is under-estimated by too many. She has always been quite skilled in the commons and has proven that her ability to politik outside Parliament is equal if not greater.
I thus propose that Leitch has an ulterior motive for pushing so hard at social conservatives.
If Electoral Reform happens, and this does indeed trigger a new "Reform Party", Leitch would be excellently positioned to take charge of that party. Nobody else of stature on the federal level is currently going after this audience, and it most certainly is possible that, if they move quickly, Leitch and a small group of currently Conservative MPs could start such a party. May 2017 is the current timeline for introduction of legislation around electoral reform, which just so happens to be same month the Tories pick their new leader. Legislation needs to be debated, and I for one think that the Liberals will want to pass such legislation prior to the summer break.
This thus gives us our timeline. Leitch purposefully isolates herself on the right among the major candidates. Chong, possibly MacKay, as the 'progressive' faction leader, wins the election, but Leitch places well, perhaps even making it to the final ballot. The legislation drops in early May, and is debated in Parliament. The leader is chosen later in May, after Leitch draws some 'lines in the sand' over issues that she is well aware the party can't support. June will come and the legislation will clear Parliament, and Parliament will break for the summer. Leitch will spring into action, and get together with other MPs, possibly including Brad Trost, Kevin Sorenson, Mark Warawa, and others. This group would then declare their independence from the Tory party, and start a new "Reform Party". While I think it unlikely they'd use the old name, they will be working hard to avoid one thing: the way Reform rose up.
Reform rose up from outside the political establishment to challenge it. This is, in fact, the tradition in Canada. Social Credit, the CCF/NDP, and even the Liberals when they got their start, all rose up from outside the establishment. If this group plans to head off that (and I strongly suspect they would; as this is the first time they may get 'advance notice' of a party creation due to the encouragement of such a thing that electoral reform offers) they will need to move quickly. This means by the time parliament returns in the fall of 2017 (probably with a throne speech) there will be another party. Weather or not they get 12 seats is still in question, but they certainly will have enough to outclass any technical grouping between the Bloc, Greens, and Independents. Nor will the party have enough seats to challenge the NDP for the 3rd position. They'll nicely slot into the #4 spot.
All of this, of course, depends on a great number of variables and assumptions. It is not a map to the next election, but rather, a possible alternative explanation as to the strategy being used. If it is correct, we might yet see far more from Leitch on the front of social conservatism.