Futurology

They shut down and relit many more engines during stage separation and the subsequent boostback burn. Here's where they relight the middle ring of Raptors.

I suppose if you want to add "in microgravity" to that list item, then yeah, they haven't done that part yet. The list item just said "Re-light Starship engines", which they have indeed done many times in many circumstances. Just not that particular one yet.