You'd need to verify with Apple since that is outside Adobe's control. However, a quick Google search brought back a few results. It looks like it might be possible to change the app's home screen icon without an update in IOS 10.3. Prior to that IOS version, it looks like it requires an update.
Thanks for the clarification. We can definitely leave this question open to see if anyone from the community has a better answer, but my answer would still apply. This isn't something within Adobe's control so I don't have a concrete answer. I'll move this over to the Experience Cloud section where mobile experts are more likely to see it.