Apologies if this has been confirmed elsewhere - but it looks like several upcoming Paramount releases are still listed on Amazon outside of the US (UK, DE)

Are these mistakes or is it possible Paramount will still be releasing titles overseas on Blu-ray?

No, its worldwide. Those sites are slower to update than Amazon US. People have been getting emails from other UK sites saying the products have been deleted.

If you still want the discs, you can still find them. In the UK Gamestation carry's new and Pre-Owned Blu-rays, of which they have alot of Paramount movies still in. The prices are fairly cheap too. I picked up Pre-owned Babel for £9.