You've got something confused here. Google's current occupancy in NYC is >7K. They were/are planning to more than double that to ~20K.

So it's absolutely an expansion of a similar scope.

empty promise is useless. did they sign a contract saying if they hire 1 person less than 25k and their average salary is 1 dollar less than 150k by certain time then they will refund all tax breaks? when bezos signs that contract then I would believe this.

Their entire deal, which was released with the initial announcement, is predicated on them creating those promised jobs and building those promised buildings. There are benchmarks along the way and all the incentives are based on meeting those benchmarks.

In short, yes, they would have signed a contract stating that.