FWIW the second part does not address my concern (which was about omitting literal parentheses that are present in the markup, in some cases), though it is related. Personally I think it's already a mistake for bare/unescaped words to indicate markup, or I guess the intention is that they indicate mathematical semantics and then Typst decides the best way to write down that semantics unless you explicitly interfere -- seems like a recipe for confusion whenever Typst's ideas of the mapping from semantics to typography don't quite line up with yours, or the conventions in your field. I'd much rather approach mathematical typesetting with a typesetting language than a mathematical language where somebody else has decided how that math should be typeset, even if it means a sea of backslashes and curly braces.

(Edit to add: I guess this means my preference would be option E from the blog post -- I see the extra symbols as far preferable to the ambiguity between content and markup)

Also wow, recovering from this breaking change is going to be incredibly painful for somebody.