The game only assumes you haven't done the events YET, although there are a few dialogue changes depending on your story progression (notably, Estinien's 3 ways when you meet again in 2.55; and Thubyrgeim having I think also 3 different options: either you completed the quest Tataru is currently doing, you didn't unlock ACN, or you unlocked ACN and took the quest but haven't completed the task Tataru is doing). Outright pretending events happened without the WoL is... unprecedented.

My best guess is that, if Dalmasca will feature in Part III; we get a differing line in case the PC didn't do Bozja. Say, Fran acknowledging meeting us in Bozja and saying it was time we helped in Dalmasca if you DID complete it, or... just saying something vague like "I've been hoping you'd meet us in Dalmasca after so long." in case you didn't.

While I wouldn't mind Part III being locked behind completion of Bozja, it'd need some heavy nerfs and reworks to future-proof it, since a player could in theory get through all of Return to Ivalice in less than one day, going from rank 1 to 25 and getting all the people necessary for CLL, DR, and Dal would be... taxing...