yes, that can happen. I had a 55 gallon tank a long time ago that was off level front to back, and the center brace failed. The tank didn't crack or leak, I caught it in time, but the front glass bowed way out, it was spooky.
Now when I move a tank or set up a new one, I use a carpenters level and wood shims to level up the stand with the empty tank on it. I check the level on the top of the tank, (not the stand) I check it front to back, side to side and diagonally on all 4 corners, and I use the wooden shims underneith the stand to adjust it accordingly.
MikeS