I agree, that coolant temp sensor will NOT affect spark.
There are quite a few reasons for a no-spark condition. The #1 suspect is the crankshaft position sensor, which you have already replaced.
Don't replace any more parts until testing verifies the failed part. I hope your mechanic has the knowledge of how to test to the point of failure. If not, find a technician who does.
Start with testing of the ignition coil. They can be tested for primary/secondary resistances very easily.
Other possibilities include a bad ASD relay or a problem with the ignition switch. The ASD relay is located in the power distribution center (black box) under the hood on the passenger side. That relay can be swapped with another relay in the troubleshooting process, as these relays are of the same part number.
Here is the route of how spark is delivered......
Spark: 12 volts from ignition switch to the ASD relay; when the key is first turned on the PCM provides a ground to the ASD relay to energize it, then the ASD relay passes 12 volts to the coil primary side. If no crank sensor signal is generated after a couple of seconds the PCM cuts the ground to the ASD relay (and fuel pump relay too) and that cuts power to the coil (and fuel pump). Key to START and once again the PCM energizes the ASD relay. Now, a critical element is the crank sensor--no signal from the crank sensor and the PCM won't trigger the coil to provide spark
99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!