Rotating seats may seem to be the brandnew system in Japan's capital area. But, more than 20 years ago, Kintetsu Railway, which is based in Kansai area, began revenue service of L/C cars. Those cars have the same function with Seibu 40000 series trains explained on the article.
By the way, I didn't know the English names of seat arrangements.
Cross Seat(Jaglish): airline-style transverse 2+2 configuration
Long Seat(Jaglish): longitudinal seating
I guess these names are not common in English-spoken countries, probably because railway fans in these countries rarely discuss seat arrangements and little chance of discussing it hasn't create a symple word for Cross Seat or Long seat.
