In his latest research note, well-known Apple analyst Ming-Chi Kuo has forecast that Apple will make a large-scale transition to ARM-based MacBooks and Macs in 2021. Previously Kuo had indicated 2021 would be when the first ARM-based Mac would ship, but wasn't it still wasn't clear that Apple would take baby steps or go the whole hog. At the time, we correctly speculated that there were good reasons for Apple to go hard on the ARM-based Mac transition and it looks as though the same rationale will drive the change.
https://www.notebookcheck.net/Kuo-A-wholesale-transition-for-Apple-to-ARM-MacBooks-and-Macs-to-start-next-year-as-we-predicted.459189.0.html