Someone familiar with Constitutional law can answer. Meanwhile consider that the Constitution mainly served to alter the form of government established by the Articles of Confederation. Nowhere does the Constitution reference prior acts of Congress and hold them null and void. For example, should we ask if the Constitution voided treaties with the different Indian tribes negotiated by Congress under the Articles of Confederation? Was the Treaty of Paris (1783) still in effect?

The Constitution nowhere addresses prior laws, debts and obligations made by Congress. Since they aren't rejected or even mentioned, they have to be accepted and considered binding. That's basic contract law. Otherwise a man could be let out of jail and be released from indebtedness if (1) his state passed a new constitution and (2) the new constitution didn't specifically 'absorb' laws passed by prior legislatures. The same would be true at a national level - tell the IRS to take a hike!

Can't imagine that anyone present in the Constitutional Convention ever considered the new form of government a means of release from all prior laws and treaties made by Congress. If that was true, the United States could clear up a lot of red ink and controversial laws and court rulings and executive orders simply by enacting a new form of government.

That would create anarchy throughout the country, but what the heck?