Does a wheel alignment always require an ADAS calibration afterward?
Short answer: Not always, but many vehicle makers require at least a steering angle sensor reset after an alignment, and some also require a camera or radar calibration; the maker's service information decides.
An alignment can change the thrust line, which is the direction the vehicle actually travels. Forward cameras and radar are aimed relative to that line, so a change in rear toe or thrust angle can leave a sensor looking slightly off to one side even though nothing on the sensor was touched.
Requirements differ widely. Some makers only call for a steering angle sensor zero point calibration after toe is adjusted. Others list a forward camera or radar calibration whenever the alignment changes thrust angle beyond a limit, and a few require it after any alignment. Look up the procedure for the specific vehicle and year rather than relying on a general rule, and save the printout.
A good routine is a pre-alignment scan, the alignment, the steering angle reset, any calibration the maker requires, and a post-scan and test drive where lane keeping and adaptive cruise behave normally. Use wheel chocks and a properly rated lift or rack when working under the car.
Tools used for this job
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.