From what I can understand from the WordPress ticket, they don’t want to implement the proposed solution in the ticket as it does break IE11 compatibility.
I am concerned for WordPress as I see 6K+ tickets, some from 10+ years and they just keep growing, while most of their work is focused on Gutenberg now, I can only imagine how many nasty things there are that are still not solved.
It would be really nice if someone can participate and maybe propose that fix if it doesn’t break IE11 compatibility. I don’t want to re-apply that patch each time. I am just not a coder and don’t know how to propose it in WordPress trac.
In the meantime, I will try to implement it on my WordPress installation.