Loans written in the last few years have been stress tested for serviceability to the mid 7% range, if you couldn't service at those levels you weren't approved so short of someone losing a job/having provided falsified income and evidence of it to get their loan a few % rate increase will not open the flood gates.
https://www.yourmortgage.com.au/mor...rs-are-stuck-with-their-current-loans/242519/
