This would be one of the goofiest ways to find out about this, but I was messing around on Universal's online retail site Gruv.com after getting an email from their rewards site. I filtered their inventory by 4K UHD and then I sorted it "Price: High to Low."
There are currently 7 listings on Gruv for Universal 4Ks that either don't currently exist or are tied up in box sets, priced at $999.99 and marked as out of stock.
Inglorious Basterds is already a pretty sure thing for 2021, but the others include:
I have linked to the listings above.