It would have a short-term boost. And as the French put it: "aprés moi, le deluge". And they would point to old literature: "Already then, we mentioned the 120 years." But the appointed time had not come, yet.
Let's wait and see. The periods with a focus on a specific year were flourishing times of the Watchtower. And as Hoffer put it in The True Believer, members in generally move together after a failed prophecy.