So to my understanding, I think the interviews are being held in batches because someone in a Facebook group claimed she did hers by the last week of January while I did mine first week of February. So there's a possibility that you can still get an invite.
DAAD EPOS by April? Isn't that the timeline for the All Discipline DAAD scholarship and not EPOS? Please can you share your source so we can verify this claim of yours?