Is it safe to make uncooked beef cannelloni with cheese and eggs, stuff the raw shells and leave in fridge overnight?  I would put the hot tomatoe sauce over top just before baking. 
Is the meat cooked or not ? it's not clear.  I would prepare the stuffing, cook it all and cool it down and stuff the cannelloni and put that in the fridge.  Personally, I would bake it all, sauce included the day before and cool it down and put that in the fridge. (I treat that the same as a lasagna). 