Resolves YES if the French national railway operator SNCF (or any legal structure that is clearly a successor of current day SNCF) operates 15 or more permanent night train lines, concurrently, at any time before Jan 1st 2027. I reserve the right to N/A on ambiguity after discussion in the comment.
A line qualifies if it has a different terminus than all other operating lines, and if it operates year-long on a regular schedule (does not need to be daily, but does need more than weekly, and not only in the summer/winter). Night train lines qualify if they are labeled as such, and contain sleeping accommodation (not just a very late train)
There is currently 6 SNCF operated night train lines (all of them of course qualify under the aforementioned criteria) with plan for another one opening in 2023. This is up from 2 in the 2010's but down from double digit numbers in the 60-70's