My kid got student visa with correspondence letter

[praveen Konithala]

Hi all

my kid and wife recently got study and sowp visa. Today my kid received a correspondence letter stating a border visa officer will decide my sons study visa approval during the port of entry. Is it normal process or a one off case. My kid will go to 5th grade. Do we need to prepare for any questions or is the school admissions to be taken before reaching Canada please advise