Idk about that. You are adding more weight with the motors and generators and you still have the ICE. If that is lighter than the transmission then maybe.
It is lighter, just a fair bit more expensive due to all the copper. That's the reason I've seen to justify why it was never adopted. Clearly not something the yanks care about, the Abrams uses a helicopter motor for zero good reason.
IIRC locomotives need the electric motors because they have better torque-RPM characteristics that lets the vehicle accelerate from standstill with 6-gorillion tonnes of freight.
Tanks need
huge torque. They're not only heavy from all the armour, they also have to spin super heavy steel tracks around (which will try to bend the other way because of springs in the bushings, which improves grip by coiling the track around rocks and stuff), and smoosh terrain with their suspension. That's why tank gearboxes are super heavy and why they need so much maintenance. Electric drive on tanks makes a lot of sense, it's just that you'd need a generator instead of a big battery. Diesel engines, generators, and electric motors are all much more durable components by comparison.
The idea has a bad reputation among War Thunder players because when Porsche tried petrol-electric in the 40s the result was useless, but with modern tech and not labouring under the same resource scarcities Germany enjoyed, it's probably the best solution. Another advantage is that you could actually move the tank on a relatively small buffer battery for a minute or two, letting you emergency start instantly without waiting a couple minutes for the turbine or whatever you have cranking the generator to get going (the Abrams takes five minutes to start due to the big turbine). Also, tanks spend a lot of time idling. A diesel-electric tank could spin its turbine down to a more fuel efficient range while it isn't moving, saving a tonne of fuel and letting it stay in the field longer. Refuelling is one of the most dangerous things a tank can do, because by nature it operates close to hostile artillery, it's not a plane that can just fly off to refuel three countries behind the front. Fuel efficiency actually matters.
It's also interesting from an engineering perspective. Without a transmission there's no need to put the powerplant at the back of the tank. The electric motors themselves are tiny, you could probably even put them inside the sprockets, so moving the powerplant up front and the crew to the back lets you put the Armata's armour bubble at the back where the crew could have Merkava-style escape doors, or just standard roof hatches which would be shielded from small arms by the turret.