Put simply, no.
In addition to having the physical space to install this equipment, the aerodynamic effects on contact wires gets pretty extreme even at 125mph, let alone taking that into normal high speed rail or even beyond. Being able to provide the structure to support this, then sufficient pantographs within the train, without detrimental aerodynamic effects upon each other would be very challenging, for what would only be a gain for infrastructure that can be gained in other manners.
Then of course there's the potentially greater issue of how to transmit all of these between the cars at the high voltage, is hard enough getting one multi kV jumper in play, let alone two or three.
Then if we assume that all power is to be immediately rectified anyway as it's likely to make use of a DC Link converter, one would not be able to benefit from a 3 phase common core transformer as for one, it would be too much larger to realistically fit with the revised core shape. But for another under the common fault conditions of loss of a single phase, this would cause significant damage to this type of transformer. So you'd essentially have, three, single phase supplies, all rectified. Rather than a three phase supply.
So in summary, it's not really helpful and it's exceedingly difficult to manage, even with relatively low speeds.
And any kind of motor drive technology that would benefit from having all three phases presented has fallen out of favour nowadays because people either don't understand it, or it doesn't provide any benefit in a rail traction environment (usually both for high speed systems).
