According to a new Bloomberg report, Apple's ARM-powered MacBooks could arrive earlier than expected. The report indicates that Apple will host a second event in November to unveil their new MacBook lineup. This means that the transition from x86 could start before 2021.
https://www.notebookcheck.net/The-first-ARM-powered-MacBook-could-be-here-earlier-than-expected-with-Bloomberg-suggesting-a-November-launch.497582.0.html