One of the execs has said both Discovery and Lower Decks will be ready to air in May, but that isn't the release date. Just the ready date.
If that shot's from the last episode, it implies Georgiou stays through to the finale, which...is not what I expected.
It can't be. I remember seeing that shot in previous photos for S3. Though I do think Georgiou will be in the entire season.
IIRC it will turn out that Michael ended up in the future like a year or so prior to Discovery showing up. The long braids are meant to show that enough time passed for her hair to grow out.