Rumour has it that Samsung will be introducing a successor to the Galaxy A71 that supports OIS. The so-called Galaxy A72 will not arrive until 2021 at the earliest, but the inclusion of OIS should yield a leap in camera performance for Samsung's mid-range Galaxy A series.
https://www.notebookcheck.net/The-Galaxy-A72-may-be-one-of-Samsung-s-first-mid-range-smartphones-with-a-flagship-camera-feature.481692.0.html
Can't they just do a software update to take care of that on the present A70 and A71 ?
It's not just a software update alone. It's an hardware issue for OIS to be included in a phone . A70 and A71 ought to have been built with OIS from the onset. Samsung take note for future mid rangers.