Seems to me the biggest problem is letting go of the payload, not because it will burn up but because of the sudden unbalancing of the spinner. The video Dave posted illustrates the issue pretty well - in most of the windmill destructions I've seen, one arm lets go and the shock of that breaks the other two arms which then let go in sympathy.
But... what if that doesn't matter? When they used to launch rockets I bet no-one ever said "No, this will never work because the first stage won't survive coming down." Losing most of the rocket is just the cost of doing business (or used to be). So what if the destruction of the wheel is just the cost of this style of launching?
Against that, it would be a pretty spectacular loss of functionality...
Releasing the payload is not the biggest problem. A small one comparing to other problems they must solve. The bigger problem is actually the centrifugal g force the payload must endure.
At 11000g, as had been said in earlier replies, the payload needs to be pretty much hard like a piece of solid object. Think about a digital watch. That little button battery weighting 1gm will have 11kg centrifugal weight! A 0.1gm IC will exert 1kg weight on the the PCB... Practically everything not solid may be crushed under it's own centrifugal "weight". The cost of hardening your product for a 11000g launch will be very high. So they are left with a very small market of potential customers.
They are launching at Mach 3. That's not enough to go into space. It will require further boost by a rocket of some sort. So the spinning launcher launches a rocket with the real payload inside. Presumably, you would want to launch that rocket nose first, that means
the centrifugal-G would be lateral. A rocket that could take 11000 lateral-g will be rather hard to do if doable at all.
Well, one could launch the rocket laying flat. Beside being clumsy to handle, the rocket will come out rotating.
All object launched by this method will come out rotating. This rotation will not be from the angular momentum of the spinning wheel launder. It will come from
unequal acceleration along the radial direction of the launch wheel different velocity due to different spinning radius. The out-side end (of the rocket) will be farther from the spinning axis as compared to the inside end -- farther by the length of the rocket. So the out-side end will shoot out at higher speed than the end that is closer to the spinning launcher axis. That unequal
acceleration velocity results in the rocket rotating end-to-end upon release. This will add more issues with controlling trajectory. This launch speed asymmetry actually applies to all loads. Even if they shoot up just a box, one side will be farther from the spinning axis than the other, so any object will rotate simply because of the chosen method of spinning it to launch.
So on, so on. The issues are endless. I can spend days listing them and can still find more after. Each solvable, I am sure. Adding the cost of researching and solving all that would be huge amount of money making this a very expensive way to launch anything -- in my opinion.
We can discuss Spinlaunch to no end, but I'm personally pretty sure it will never go anywhere while having eaten a ton of cash. Where's the popcorn?
SiliconWizard is right. I too am pretty sure that it will not go anywhere. With that in mind, while
SiliconWizard can go for his popcorn, I have a lot of left over turkey to finish...
EDIT:I use the word acceleration in two places instead of velocity. While the physics is still technically correct, it is the velocity that matters on release. The wrong choice of word made the paragraph difficult to understand. So, I did a strike-out of the old and replace with underlined words.
Unequal acceleration was on also my mind because: there is another unequal acceleration that bends the rocket since the rocket is straight and spinning traces out an arc. But I decided not to include that.