Sentinel files were also intended to provide a means to partially recreate characters on private servers. They are not merely text files (if you have one, check the final line...you'll probably see what I mean). As such, they could theoretically be used to verify that a claimant is the true owner of each of their characters. If NCSoft hands over the character data but not the account data, we couldn't verify who's who by using passwords, but Sentinel files would be the next most reliable way to re-verify players to characters. There might be other ways, depending on how flexible the CoH i23 operations team is, and what records each player kept offline - akin to a "tell us the name of your characters' third grade teacher" re-verification process. Heh.
Still, this is putting quite a train of carts in front of a horse that might not exist. I'd suggest waiting until:
1.) the purchasing team reports success but without account data from NCSoft,
2.) an expert figures out exactly what (if any) character data is included,
If character data exists...
3.) the CoH i23 operations team decides whether (and precisely how) they will allow players to re-verify ownership of characters. Sentinel might be just one of several options.
If -no- character data exists...
3.) the CoH i23 operations team decides whether to give help toward recreating characters in-game (such as XP boosters, various types of merits, and cash shop credits)
and whether that aid will be equally given to all, only provided in proportion to the value of items* held by verifiably-owned characters, or available to those who pay for it.
4.) whether private server options will be made available for either CoH i23 or CoH 1.5.
*this could be easily restricted based on the knowledge of Sentinel's blind spot (transfer of Inf and enhancements from character A after Sentinel save to character B before save). It would also be fairly easy to catch a cheater who attempts to get proportional aid to rebuild multiple characters by submitting files with items duplicated in that fashion.
Many questions, few answers at this time... but that's to be expected.