I would like to suggest that breaking changes to the default parsing options in @formatjs/icu-messageformat-parser should also cause a breaking change in intl-messageformat.

I recently updated my project to more recent versions of all @formatjs deps and intl-messageformat. There was a breaking change in the @formatjs/icu-messageformat-parser which correctly caused a major version change, but my project only depends directly on intl-messageformat directly, so I didn't notice the change.

As a result, I ended up encountering a large number of MISSING_OTHER_CLAUSE errors. After chasing some down 1-by-1, I ended up with a diff like this:

+import { parse } from '@formatjs/icu-messageformat-parser'
... some other stuff ...
-    const parsed = new IntlMessageFormat(formatstring, locale)
+    const ast = parse(formatstring, { requiresOtherClause: false })
+    const parsed = new IntlMessageFormat(ast, locale)

Just wanted to share this experience and ask what others think. It's not exactly a "bug", but it did cause unexpected breakage for me.