It is supposed to be there. When I was at the printer going over the proofs, there was a blank page on the back of the last scenario, since there is one scenario big enough for two pages.
Instead of leaving it blank, I picked the next largest scenario and copied it to the back of BFP-25, so both sides can have a copy during the play of BFP-21.
I couldn't just pull a new scenario out of mid-air and publish it, so I thought an extra copy of a scenario would be better than a blank page.
It is unprecedented behaviour, but thanks for the oppurtunity to explain here.