From the Constitution:
“If any Bill shall not be returned by the President within ten Days (Sundays excepted) after it shall have been presented to him, the Same shall be a Law, in like Manner as if he had signed it, unless the Congress by their Adjournment prevent its Return, in which Case it shall not be a Law”
The pocket veto only works if Congress adjourns. As long as Congress is in session, the bill automatically becomes law when the President signs it or in 10 days if he doesn’t sign it.
Also from the Constitution, right before the passage above:
"Every Bill which shall have passed the House of Representatives and the Senate, shall, before it become a Law, be presented to the President of the United States".
If he's not President, then that was not satisfied for anything passed since Jan 20, 2009.
No presentment, no law. (The second "shall" makes it mandatory. Now, they could present the bill again, to Biden, if he was acting as President before a President could be qualified, and sadly he likely would sign it.