There is a Musashi (Yamato class) EBB in testing at the moment, but wether it will be ready for EBB release I do not know. I'm unsure of the current test patch status, at this late a stage (since the deadline for EBB balancing was jan 7th) it may not be ready, since it was provided by SDE much later than the other new event ships. This is also the case for the UK EBB5 the Vanguard '46