On my website I have “Markdown Extra” installed for ages (blog is nearly 14 years old). Jetpack is installed but it’s Markdown plugin is disabled.
Checked my old posts and in database they are still Markdown as I wrote them. I do not edit them (even if their grammar could be improved) so converting to html would not be an issue.
The problem is that Gutenberg editor fails to show Markdown code properly even in ‘code editor’. Listed lists for example are flatten to one list. After installing ‘Classic Editor’ plugin they are presented properly.
Probably will give a chance to one of plugins which allow to select classic/gutenberg (like ‘Disable Gutenberg’ one) to be able to use both Markdown in old posts and Gutenberg in new ones.
Any update? Wordpress 5.0 is next week and it looks like it makes Gutenberg mandatory.
My blog is 13.5 years old and I use “Markdown Extra” since nearly beginning. If I have Gutenberg enabled that all my old posts gets mangled. All links are not parsed etc.
[url description](url) format is what I use for years.