Reheating no boil lentil lasagna noodles after freezing
Thawing will always result in somewhat mushier texture than freshly baked pasta.

I'm not familiar with lentil pastas, but I would expect them to be mushier after thawing compared to regular wheat flour pasta.

If you intend to prepare your lasagna in advance for lunches (for example), you could undercook the pasta a little bit so that it finishes when reheating.