Speaking as someone with experience in enterprise software, I'd say there's a good chance it's because one or more large corporations were ready to migrate from

Speaking as someone with experience in enterprise software, I'd say there's a good chance it's because one or more large corporations were ready to migrate from MS Office to Google Workspace but that not having Markdown import/export would be a deal-breaker. A lot of times when you wonder, "why did they add that feature?", that's why. A single large potential customer absolutely needed it because of whatever critical internal business processes they happen to have. It's a major difference from software sold to consumers, where the aggregate consumer demand for a feature is generally more obvious/intuitive/explainable.