When the tax breaks end, Amazon will Flee
Happens all the time. Companies like Verizon promise thousands of jobs, if only those pesky taxes didn't get in the way. Local community passes a deferred tax agreement. Verizon builds a call center, operates for a few years tax-free. Tax agreement ends, and oh look, Verizon moved.
If you PAY the company to move to your city, they won't have any problem getting someone else to pay them to move later.
As others have pointed out, multi-billion dollar sports franchises do it all the time.