Very unconvinced. The engines provide motive energy whilst the APU is shut down. They also provide electrical power and airconditioning through compressors. So this system uses APU alone to provide all that electrical energy (considerable!), enough to get a heavy aeroplane up slopes, as well as providing compressed air for cabin conditioning. Going to take a far beefier APU with an enormous alternator to provide that energy...which will burn far more fuel than APUs currently do. Then, we're going to put those electrical motors in the same space that brakes currently occupy in wheel hubs, where they will not only get roasted to oven temperatures from -60 degrees C, but regularly doused with large quantities of water and dirt. And the downside, apart from first cost and complexity of maintenance, is significant extra weight of these large motors being carried throughout flight.
I'll believe it when I see it working reliably. Which it won't.