The only instances I could find in which Citroen could have asked Sordo not to challenge Loeb are Catalunya 2007 and Catalunya 2009. Maybe New Zealand 2008, but was a particular case, as Hirvonen and Latvala threw the rally away at the penultimate stage while they were 1st and 2nd.
I think he was sometimes close on tarmac and that would create some pressure, except both would know that they will hold position. Anyway overall he was under control and never a danger to Loeb in the championship.
Tarmac rallies are part of the WRC challenge for drivers.
And having the Championship in a major European capital city will bring great publicity to the sport there.
From beginning it is mainly about Rally2 car. But still there is question how 2027 will looks like in general...
WRC mainclass from 2027