What evidence do you have of any of this? The 2017 rules are perhaps the most significant overhaul of the regulations since the introduction of World Rally Cars in the first place. There's no way to predict who will have the better car. Your entire hypothesis seems to hinge on the assumption that if Loeb wants to return, it will be with Citroën before anyone else.
I've already covered Toyotas situation in my previous post. The project has too many cooks and when they should have had an advantage over everyone else, they're now behind schedule for 2017. They lack the organisational experience and general knowledge of the modern WRC calendar too.
Hyundai have spent much of their time working on a car that's relevant for a year. Sure some of it will carry forward but they're on the back foot compared to Citroen and VW in terms of development for the 2017 car. They do however have a strong 2016 car which sort of leads into VWs problems.
Volkswagen we know have been testing the 2017 for quite a while now. It'll be really, really good I'm sure but they've still got to keep some of the team back to continue working on the 2016 car so they can win the championship again. Ideally they'd like to have halted development altogether on the 2016 car but Hyundai have come along with a brand new challenge at the most inconvenient time possible.
M-Sport apparently don't have the budget to finish this season so I won't go any further with this.
Citroen only have to focus on making the new car. They don't have to worry about the championship, they don't have to worry about who will drive the car, they don't need to worry about the rallies themselves restructuring, they don't even need to send team members to rounds which they contest as PH Sport are more than capable of preparing and running a car for the weekend. They've even cancelled the WTCC program to focus absolutely everything they have on this 2017-spec car.
I don't believe the Citroen will be good because Loeb might return to them, frankly I don't care if Loeb returns or not. I believe the Citroen will be good because they're in the strongest position leading into these new regulations and they've got plenty of talent behind the wheel as it is with Meeke, Lefebvre and Breen.