From Liberation.fr (use Chrome to translate the article to your preferred language):

“There are only two lines still in operation: Paris-Latour-de-Carol, connecting the capital to the Spanish border, and Paris-Briançon, which joins the Hautes-Alpes. A sign that the situation of night rail links is still very fragile, the latter is under construction until the end of the year. The government has promised their survival.
“We are also waiting for the imminent return of Paris-Nice , delayed by the health situation, as well as that of the Paris-Tarbes-Hendaye line , "the Blue Palombe", by "the end of the year", says the government.”

Here’s a cool map on the current and future state of things:

The slow return of the night train (Alice Clair / Julien Guillot)

Red in currently running, dashed red undergoing works, pink is ‘coming soon’, and blue is what there used to be.

A couple of things to be excited about:

the train that will go from Paris to Tarbes looks like it will then go on to Hendaye/Irùn on the French/Spanish border. From there it’s a 30 minute train hop to a nice relaxing breakfast at a beachfront Café de la Concha in San Sebastien. Yes please!
The Paris - Vienna route is opening at the end of the year. Maybe not right at the start—but hopefully quickly—the wagons used will be the awesome brand new Austrian-built Siemens ones with new bedroom designs as well as individual sleeping pods. Yes please!

The lack of news about any other European service provider looking to redesign sleeping wagons for the 20th century is however a little disappointing. Push for it!