If it was the third grand final in the last 105 years then North Sydney do indeed qualify.
Well, not really. But close. They've been premiers twice (1921, 1922) and runners-up once (1943). They played and won a decider in 1922 when they were locked on the same points with Glebe. This was their only victory in a decider. In 1921 the competition lasted 8 rounds and they were first past the post so there were no finals. And in 1943 they were thrashed by Newtown in the Grand Final. That's all there is to report.
On the other hand, North Sydney have won three wooden spoons in five years, twice. (1915-19 & 1948-51)