I read an article reporting an interesting experiment for the Shinkansen users (the article is written in Japanese).
It is still at an experimental phase and you cannot have this service in every single Shinkansen. Apparently, some particular compartments of Shinkansen allow you to use the space a bit like your own office; wi-fi is provided and nobody is bothered if you take a conference call (it is a no-no to take a phone call in train in Japan). Since it is at an experimental phrase, you do not have to pay any extra fees to use this special service.
It sounds a great idea; I would perhaps appreciate it if I have an imminent deadline or something. But to be honest, I would prefer to be relaxed with a nice bento box and my favourite canned coffee in Shinkansen ????☕ … (;^ω^)…