Never say never.
I personally believe Apple accounts for a certain refresh lifecycle amongst its various class of users For example they have some data that shows an average iPhone user keeps their phone for 3 years (that’s made up, just using it as an example), therefore the class of user that wants a small factor phone would hold onto their 13 mini for 3 years before looking for a replacement. So I predict a small form factor to come back in the future. In the meantime, the mini form factor takes a break since there would few if any sales as the current lot of mini lovers are still within their ownership cycle. Same logic that applied to the incremental iPhone -> S variants. iPhone 3 owners would go to iPhone 4, while iPhone 3S owners would wait it out for iPhone 4S
remember how the original iPhone SE came out of nowhere to save the life of iPhone 5 lovers After a bit of time?
id guess some future iPhone SE in a 13 mini body in a few years, or a new small form factor phone