If states did not submit electors would this not be the same as if a 3rd party candidate had won some states and prevented any candidate from winning 270? The election would be determined by the contingency procedure established in the 12th Amendment.
There is no third party candidate. The procedure for 2020 would be determined by the Electoral Counting Act (1887). And that applies to states no sending elector, or trying to send two conflicting sets of electors.
Under no circumstance can Trump take away EC votes by changing the already cast vote count. What he is trying to do is prevent EC votes from being cast at all, but only in certain states, by December 8th. He needs to get Biden under his 232 EC votes, and not under 270. Because Trump cannot win with Biden at 269 EC votes and Trump at 232.
And that would involve completely disenfranchising all of the voters of a state, regardless of who they voted for. I don't think it would go over well with the voters of Michigan, or any other state, to say "sorry, you wasted your time voting, but your votes don't count". This will not happen.