That was not misinformation. In my year (of Rabbit) we were really accepted right in the 3rd interview. Of course I'm not sure if everyone getting 3rd-in got accepted right away (as we arrived a bit earlier and we could see some families came out with great happiness/smiles and some didn't, and we saw the list of student was more or less than 20 names). We also didn't know in advnced so we were very astonised and happy when we knew our daughter got accepted in the mid-way of interview.
There might be really a lot of applicants in last year (of Dragon) so there're still many candidates until 3rd round and the school needed some more time to choose. I believe the school has different treatments year by year.