I doubt there will be an instant massive stampede of new foreign teachers. A lot of people who wanted to come to China over the last few years have found other things to do. Also, Z visas require paperwork and Spring Festival is nearly here. There will likely be more competition for FT assignments later, but my best guess is that we're looking at Fall 2023 before competition levels begin to rise significantly and 2024 before it reaches a level comparable to 2019.
What I do expect to see a lot more of is reps from foreign companies showing up to check out the factories of Chinese partners. A lot of these used to make several trips per year, but quarantines were enough to make many reduce or eliminate visits. Once Spring Festival is over, business class seats on airplanes will be in much greater demand.