Considering the fact that according to the
Wikipedia article on the Class 373 only 5 of the French-owned sets with numbers 3732XX had/have 1500 V DC capability I went through the list of sets on that same article (brackets give sightings in the South of France/Alps):
373201/373202 scrapped
373203/373204 scrapped
373205/373206 refurbished
373207/373208 in storage
373209/373210 refurbished
(sighting 373210)
373211/373212 refurbished (373211
sighting 1,
sighting 2;
373212 sighting)
373213/373224 Thalys TMST (sightings
373213,
373224)
373215/373216 TMST (sightings
373215,
373216)
373217/373218 TMST
(sighting 373218)
373219/373220 refurbished
373221/373222 refurbished (sightings
373221,
373222)
373223/373214 TMST (373214
sighting 1,
sighting 2)
373225/373226 scrapped
373227/373228 scrapped
(sighting 373228)
373229/373230 refurbished
(sighting 373230)
373231/373232 scrapped
But surprisingly, this gives a significantly larger number of sets with 1500 V DC capability than there should be. Not sure what's behind this or if this has maybe got something to do with some renumbering. But it does seem like quite a few of the unrefurbished sets have 1500 V DC capability.