Are you aware of a policy that allows Strava when within sight of shore, but bans it when under more sensitive operation?

Or is this article perhaps better interpreted as an example of a dangerous behavior that could be happening also during those sensitive times (in which case, it is unlikely that French media would be even running a story with a map of the sensitive location)?

This isn't a novel problem.

Detailed maps of military and other sensitive areas have been created through run maps from fitness watches[0].

[0] https://www.theguardian.com/world/2018/jan/28/fitness-tracki...