Cloud has nothing to do with it.
All of the cloud and cloud-native talk has nothing to do with it. The *one* enabler for ARM is open source software. When entire ecosystems are available as source code, you can recompile them for another architecture. Full stop. It has nothing to do with cloud and certainly nothing to do with AWS. A private cloud or even an on-prem data center can move to ARM just as easily *if* the source code is there. If the move to ARM is a win, that win is credited to Linux and Open Source alone.