I’d argue that cdg will have exactly the same number of terminals in 2027 as it has now. Whether you name it 3 terminals with 5 concourses and 3 sub concourses or 7 terminals with 3 concourses, nothing has been built nor destroyed, opened nor closed.

if anything, if you differentiate between a terminal and concourse by the ability to walk between them airside as within a single space without having to exit or clear security, then maybe a far more useful modernisation of cdg would have consisted of “concoursing” rather than “terminalling” and thus creating new options that can fully fluidify movement within the current t2 as an almost fully barrier free environment except for connections from high risk destinations but that would have taken a bigger and bolder redesign and some new construction.

in many ways, the current trend seems to be towards single terminal airports including giant ones (eg Istanbul, Doha, Beijing Dianxing etc) rather than the very 1979s like US design of fractioned terminals dedicated to specific airlines. In fact, even lax has tried to move slowly from the latter towards something closer to the former…