Calorimeter measures heat released by the chemical reaction (for example - combustion, neutralisation....). But - calorimeter is not 100 % isolated from the surroundings. That is why some heat of the reaction is lost - depending on construction of the calorimeter and temperature of the surroundings (lower temperature means that the more heat is lost). In case of accurate measurement difference in max. temperature and final temperature (0,2 C) can be used to deduce degree of the lost heat.
In my opinion you are somewhat right, because they asked you to write "final temperature", when they should ask for write "maximum temperature" to calculate ΔT.