Actually, having been to Russia, I got to ride those cars (they are a standard design throughout all the major cities of the ex-soviet union), and I must say that though ugly and practically bare, their traction is actually pretty good. The model I got to ride in (it looked just like the one in the picture, but I was told there were many similar ones) was built in the early to mid 70's, it's a followup to a similar design that was built in the 60's, that's why they look 60-ish. Some are still in service, even though now they are actively being retired. They have a maximum speed of about 100kph (60mph), as opposed to the Hawker-Siddley's 40mph, and wicked acceleration.
Despite those couple of pluses I just listed, they also have: no A/C, no recycling doors, no chimes, no passenger safety systems, no accumulators (their lights go out at every power cut-out point), they have windows that open (!) for ventilation, as there is no AC... need I go on?
Plus, their length is longer than the red line's cars, AND their width is wider than red line cars. So even if the T would have gone completely mad and would have wanted to bring those disintegrating oldies, they would not have fit on the blue line. Not to mention that there is no way in this quantum universe that the FRA would approve them
Nice April fools, but a little too obvious.