In T8984#147453, @aacid wrote:

I already disagreed that method is the correct solution, so no it's not "the same way"

Well, I said the same way we'll do it for the formatting, so if we'll go with “all placeholders are locale-formatted”, then we'll go with “all placeholders are enclosed with isolation characters” :)
I'm with you that it's better to not let translators struggle with it, and make it the “by default” thing.