Update: as of today (Jan 6), the notarization is going through in 10-15 minutes. Not sure why it was stuck in the queue for over a week, but glad it's working now. Hoping everyone else reporting similar issues on this thread is similarly unblocked too.

Still stuck In Progress and no reply on the support ticket after 2 days. Guess it’s a new year’s slowdown?

Quick update for anyone following along: it's been about 12 hours and notoraization is still stuck in In Progress status. I submitted a ticket to Apple Developer support last night too. Stay tuned!