A basic consideration of the energy involved should tell you.
355mm radius disc, mass 1kg, moment of inertia is 1/2 mr², so 0.06 kg.m² [1]. This ignores all inertia of the arbor and motor rotor, mind, which is possibly significant (smaller radius but dense, depends on the transmission whether the motor is part of the blade system - if there's a clutch or belt to let go, then the motor isn't really part of the problem, but it's also not going to be part of the solution), Say it spins at 4000rpm, or 420 rad/s (some saws go to 6000 plus and this is quadratic).
So kinetic energy in the blade alone is 1/2Iw², or 0.5 * 0.06 * 420², or 5.2kJ. For comparison, a rifle bullet is about half that, which seems right ballpark on the face of it.
So to remove that energy in 5ms (SawStop's claim) is 1MW, or a current of 4000A at 240V, or 8000A at 120V. I don't know if any big saws run on that voltage in the US (may small ones?), but let's take the lower rest-of-world figure anyway. That's roughly 1300HP or 4 top-spec Tesla Model Y's at full throttle (320kW each).
This is not completely technically impossible to deliver - you need about 400 0.1 farad capacitors charged to 250V, which are 100mm in diameter and 250mm tall and around $150 each, so a fridge-sized box, maybe two[2]. Some very large and pricy solid state switches will be needed too, and some nice copper busbars to get the current where you need it. Actually pushing 4000A into a motor winding for 5ms isn't that easy either as it's a canonical example of an inductive load, so you need even more current, plus hopefully a way to stop the current when done before turning the inside of the motor into a plasma ball. Evaporating the motor winding before you've stopped the blade is no good, and it'll be nice to use the saw again, so you'll need to uprate the coils massively, which will make the motor very heavy, very large and very expensive.
There are probably other issues like induced voltages far higher than main voltage the will need management. As mentioned earlier, you will also not be able to use, say, a belt drive - the motor needs a very stiff physical connection to the blade.
So, you won't break physics to do this, but it will be large, heavy and incredibly expensive. $50k in caps alone.
Flipping the blade physically away from the obstacle is a much better bet. Which is actually SawStop's real trick - all that kinetic energy in the spinning blade system is grabbed and harvested to move those kilos of steel down and away in a few milliseconds. Stopping the blade is just a handy side effect of stealing all the energy. You could possibly do the same with an electrical system, but it would still be very large and very heavy compared to using the exact same huge kinetic battery that will always be there (or it's not a table saw) and which is actually the threat to safety in the first place.
It's actually quite interesting to see the relative weakness of electrical forces illustrated this way. Even quite prosaic mechanical objects can develop powers that require electrical systems the sizes of small rooms to rival. And again, chemical systems contain more power still: all that spinning mass is the energy contained in a few grams of gunpowder.
[1] Edit: I double counted a factor of 1/2 in the MoI - it's actually more then I first estimated!
[2] Another underestimate as you really need a lot more as you have to get that energy out fast and you can't wait for the slow tail of the discharge curve to finish. Plus at least Nichicon only seem to go to 160V for 0.1uF!