French military engineers / DGA always go for the most reliable system, with the lowest maintenance, space and weight , either for the submarines or the fighter planes. No Dassault planes have a retractable fuel probe for that reason.
Even if a SSBN has a lot of space, if the need of a retractable towed array has been evaluated to have more drawbacks than advantages, the space could be used to add more food, more redundant systems, more noise reduction systems, ......
And yes French SSBN have Towed Array but not internal.
The US subs had snap on until the 70's, here some stories:
https://www.quora.com/Is-a-towed-arr...t-always-towed