Based on the press release, it would appear that All Nippon Airways is buying parts of Pan Am that Pan Am Systems (formerly Guilford Transportation) already sold off to another company back in 2006. I would guess that Pan Am Systems, and its subsidiary Pan Am Railways, will not be affected by this transaction.
I believe Pan Am Systems still owns the rights to the Pan Am brand, so it's doubtful that they'd have to give it up. On the contrary, they may be receiving licensing fees/royalties from other companies that are using the brand (such as was the case with the "Pan Am" television series on ABC).
Pan Am Railways — Boston & Maine/Maine Central — Delaware & Hudson
Central Maine & Quebec/Montreal, Maine & Atlantic/Bangor & Aroostook
Providence & Worcester — New England — GE Locomotives