Bismarck's success was not needed for a 15-inch German twin refit

Would a successful Bismarck sortie lead Germany to upgrade its smaller twin battleships with 15-inch guns?

The upgrade was already planned, so Bismarck's success was not the necessary trigger; the refit would move the ships toward Renown-class firepower.

The 15-inch conversion was already part of German planning. Bismarck's hypothetical success would therefore not be needed to initiate it. Twin 15-inch mountings would bring the ships' firepower closer to that of the Renown class.