Yes, it is.

You can not take off if your planned weight at touchdown will exceed your max landing weight (for the runway and expected conditions). If landing weight plus planned fuel burn is more less than your MGTOW then your max takeoff weight is limited to max landing weight plus planned fuel burn.

What usually happens is that you end up flying a route which is shorter than the routing on which the flight plan was calculated. Often this is due to a route being planned to go around storms then a shorter route is found once in the air (storms move between the time that a flight plan is made and the flight actually reaches the area).

If can also be due to winds being more favorable than planned but this wouldn't be a big factor on a relatively short RJ flight. That would come more into play on a coast-to-coast or longer flight.

Lastly, if you took off right at your landing weight limit (max landing weight plus planned fuel burn) it's each to be a little bit under burn requiring an extra few minutes in the air before landing. To avoid holding, many pilots will descend early or create drag (gear, flaps, spoilers) to increase the fuel burn rate.