Ha, sounds like our answer is "maybe yes, maybe no."

It's been a long time since I transitioned directly from one bike to another, and I really don't remember having an experience like yours. But I can tell you that when I was commuting long distance in the car, I was always sore for a couple of weeks when I got a new car. My body just had to adjust to a slightly different position.

It sounds like you're only having muscle pain? That's much better than having joint or nerve pain, anyway. Is your riding position radically different from your old bike? Have you been doing core strengthening exercises?

As long as you're not having joint or nerve pain, if it were me, I'd give it a week or so of consistent riding, do a lot of stretching, keep up your core workouts, and see if the pain starts to resolve. If not, then it's probably time for some fit tweaks.