My experience says that you…
My experience says that you shouldn’t flush the ATF unless the fluid has been damaged by overheating. Despite the best efforts by OEM to remove contamination during gearbox assembly, there is almost always some small amount of debris in the transmission when new. If you’ve driven 45K miles with minimal problems, that debris has found a “safe” place. Draining and flushing stirs it up and it can end up in a valve or clutch and lead to poor shifting. There might be other issues too but again, unless you’ve been pulling a heavy load on a hot day or your transmission oil cooler leaked, changing the ATF is more likely to cause more problems than it might fix.