The sad fact of life is, if a Captain aged over 60 were flying in command over French Airspace and had to divert to land on French soil, that captain puts his licence at risk if discovered by the authorities to be in breach of this daft regulation.
Until the rule is changed, or unless inpossession of an exemption (if such things are possible), a company should not put a commander in that position, and a commander should not accept a duty that puts him in that position.
Continuing to operate over France in breach of the regulation is a risk - the potential repercussions of which must be weighed up very carefully.