I'd say it depends on the franchise, and the film in the franchise.
I don't see how 105m is a great number for the finale. The finale being the lowest OW of the franchise, and finales are typically the most frontloaded, means something went wrong with your franchise. Either your marketing became complacent, people didn't like the last installment, etc. Something happened to make people not care about going to see the conclusion to a series they've already seen a few installments of.
I'm not saying it's a flop number, but it certainly is a disappointment for a finale.