So, do you believe in the GOP's Supply-Side Economics (and the Laffer Curve) or do you believe in Democrats' Keynsian Economics?
I'm not an economist. My take is : Hang on, we could be in for a ride.
Even if the "Gig Act" went into force, all one need do is claim enough deductions to avoid over-withholding.
... You can legally "claim" enough on that form to reduce the withholding to zero, or (for others) to near the amount you might actually owe at the tax deadline, over even to have too much withheld if you want a nice refund (and do not mind lending the government your money at zero interest).
Just in case any reading this do not know about this tactic...you do need to report the correct number of deductions on your tax form so that even though you might say 10 deductions on your W 9 when it gets to the 1040/1040A you need to use the correct number on that form (1 if you are single and not blind or some other reason you get an extra 1 for example).