New Trek 1.5 wheels need to be trued after 2 rides, normal?
I'd say it can be normal because there are many factors can stress a wheel and depends on the quality of the wheels, they might need to be trued again. There's an article about how they build wheels at Bontrager: Inside Bontrager Wheel Factory.

tldr;

Expensive wheels are trued, stressed, trued, and stressed again, trued again. Your wheels were trued in the factory (maybe only once), then you stressed them and now somebody needs to true them again.