It's true of Hillary, but not true of Biden. Biden got his own electoral votes for VP. True, Obama effectively appointed him, but only through the mechanism of the Democrat Party convention. Thus Biden would still be VP, or VP elect depending on the timing. But if the DQ came before Thursday, the House would need to pick McCain, as the only other person to get any Presidential electoral votes. If DQ came after Thursday...
If a President shall not have been chosen before the time fixed for the beginning of his term, or if the President elect shall have failed to qualify, then the Vice President elect shall act as President until a President shall have qualified;
Amendment XX, Section 3
Finish the statute. It says right after that, if a President cannot be qualified, then the House will choose the President.
The House is under no obligation, whatsoever, to make Biden President after Obama is disqualified.