It's an absolutely ridiculous allegation, but the Macron's have decided to go for libel so they have to provide evidence.
Celebrities in the UK advise people not to sue for libel because you allow for everything to be dug up and have to provide an absurd amount of evidence (but a lot less than in the US).
I never stop growing amazed at how anything can be turned in the TRA's favour. Stating this case is forcing ALL women to prove their sex because someone thinks they're male, so best never to ask for evidence in ANY circumstance and let lying biological males off.