I might not be following you. My take is that: If the electors vote as instructed by the voters for Obama-Biden, and then Obama is disqualified, we get President Biden. But if this were to go down before Dec. 15, the electors would still be who they are and would get to vote for anyone, which would send the whole mess to the House and Senate for lack of a majority unless someone got to 270.
At most we'd get "acting President Biden". Because that is what the Constitution provides. Only if the President elect dies between the time Congress finalizes the process (Jan. 6?) and inauguration (Jan. 20) does the VP elect become the President.