Consecutive years where the premier finished out the of the finals the year before

The only time it has happened was actually three in a row:

Torrens finished 6th in 1932; won it in 1933
Glenelg also were 6th in 1933; won it in 1934
South were last in 1934 and won it in 1935

The last time consecutive premiers that were different clubs both finished out of the finals the year after (Norwood 2014, West 2015; both out of the finals this year) was 1935 - Torrens finished 5th in 1935; with the reigning premiers finishing last the year after for the first time since Glenelg in 1935....

...so, with 3 of this years finalists being different than last year, there could very well be another instance of the opening stat happening again.