Unless it's delivered from long enough range for plunging fire, which Yamato certainly can.
Plunging fire does not exist in WoWS due to auto-bounce mechanics and compacted ranges, any shell striking at over 60 degrees automatically deflects unless it overmatches. Due to the truncated ranges basically nothing in the game has a steep enough angle of fall onto decks to ever get below this, and effectively no citadel deck armor is ever thin enough (32mm of less) to over-match through. This has the somewhat stupid effect of making 35mm of deck armor worth pretty much the same as 350 and punishing any nation or design that balanced or emphasized vertical over horizontal protection, but it is what it is.
Its thus literally impossible in 99% of cases to fire from far enough away to citadel through deck armor. Yamato is actually a very rare exception, it's theoretically possible, but you would need to take the range extension mod AND have spotter plane up to manage it. As I recall you start getting just under the autoboucne angle at like 27.5 to 28km, which is also toward the end of it's range even modded that way. Even in this instance though you only get out of auto-bounce, not out of the ricochet zone (45-60 degrees), so it would still basically be a crap shot if it went through, and with many BBs having two decks above overmatch thickness the target would get two ricochet rolls as well, significantly reducing the probability of a cit.
