There are thousands of mobile processors available in today’s market, and unlike the standards of Intel vs AMD, I think it would be impossible to provide a satisfying answer on that support doc for the processor requirement. That said, the processor isn’t the issue.
I was able to investigate this further—with some help from a friendly tech support rep—and determined this phone model’s operating system does not meet the requirements for the app. Diablo players were also running into this issue, and the staff addressed it:
Samsung Galaxy A13 and A13 5G devices will unfortunately not be supported with Diablo Immortal due to a 32-bit limitation on their Android operating software.
Source: https://us.forums.blizzard.com/en/blizzard/t/diablo-immortal-hot-fix-updates-latest-update-6162222/23544
Samsung chose a 32-bit version of Android for this phone model, and the WoW Companion app requires 64-bit Android. That’s why Google Play told you it’s not compatible. This limitation is listed by Blizzard on Google Play in the app details:
Note: support for 32-bit builds has been discontinued
Source: https://play.google.com/store/apps/details?id=com.blizzard.wowcompanion
The staff added this info to the Battlenet support doc for more visibility, but there’s no way to force it to work on that phone model.