"Should" in reality? Whatever the rules say goes for the paper trail.
"Should" for me? You can't rerun the race that would have had utterly different dynamics, and reshuffling has become so common place, even with only half our eyes open, that I kinda stopped caring.
In general, I wished that if a podium spot becomes available through retroactive elimination, people should indeed move up a spot, but only if they can pass the exact same level of tests that triggered the elimination.
If they can, brilliant. If they can't, even if it is through no fault of the rider, say because we simply don't have the same amount of test samples left, or worse, any samples at all, than the spot should remain open.
With the fairly ad-hoc testing procedures we have in place, it is a mockery to eliminate and vilify the one you did scrutinize, but glorify the one that simply missed (most of the) testing points, and wasn't put under the same microscope.
I guess that makes me an "other". Option 2 or 3 depending on the above.