Is Myofascial Release As Part of Lymphatic Massage Damaging to a TT?

It is unlikely that myofascial release techniques could undo the muscle plication of a tummy tuck, but it is also probably more vigorous than is necessary. You want the fascia layers to adhere after a tummy tuck, so focusing more on lymphatic drainage techniques is probably best.

I recommend lymphatic drainage massage to my patients. This is great when combined with ultrasound. The therapist should monitor whether acumulasion liquid occurs during therapy or seroma as this should be drained
If you are feeling like You have liquid do not think and go see your doctor
In your case something important is that there is no reason to work on the muscle fascia plication.