Interesting article but clearly does not meet the needs of large companies where there are multiple scenarios to cover.
That IE 11 is not replaced is need applet, active x, etc., are still present in core applications.
Why hasn't Microsoft integrated Edge in IE11?
How to perform SSO between different applications with a main access point if each one is executed by a different browser? I think we should think more.
What strategy do you propose while you migrate?
The solution installs whatever you want, it's a bit basic.
Finally, I think that the browser is a facilitator and should not be a limitation if an application should work in IE11 because there is a period of coexistence this should not be a problem when the period ends the application will continue to work in new browsers.
It's just my opinion, thank you.