Usually datacenter will charge for cross connect, two of our racks is within same zone, does wifi connection stable enough to replace physical cross connect?
Unless the wifi is intended for administrative access, this would not be a great idea.
You will encounter all kinds of interference and increased latency. Your server cabinet is most likely bonded to the ground and essentially amounts to a Faraday cage. Not to mention all the other large metal objects in a datacenter that could cause interference.
The datacenter is also very unlikely to allow you to stick antennas outside of your cabinet to improve the signal.
Point-to-point wireless bridges such as these work very well and are widely used. However, they are typically deployed on rooftops where unobstructed line of sight can be established and are used for pulling connectivity into a building where fiber is lacking.