I don't know if this is a seiyuu joke any more than it is a "same artist" joke. There's no artist commentary to indicate it's either.
To me, it just looks like a combination of "Underdressed Nagamon" and "Shimakaze's outfit is lewd" jokes.
Agreed. Usually one can assume an implicit seiyuu reference if there's no other clear reason why a character is dressing up as another. Nagamon, however, has a lot of in-universe reasons to dress up as Shimakaze, Nagamon (Baciusverse and Fandom Nagamon) being a pervert being the main one. From a meta perspective Shimakaze's uniform is also memetic, with artists sticking other shipgirls (and characters from other copyrights and original chars) into Shimakaze's uniform just for the sheer lewd/lolz factor (Bacius also did it for Yamato and Musashi).
Kuma dressing up as Jintsuu may qualify though, even if there's no explicit reference or hinting, because Kuma doesn't have a clear reason to cosplay as Jintsuu (in-universe or non-VA meta), so one can assume seiyuu_connection in this case.
my sweet destroyer. Just like how a Battleship like myself has taken the appearance of a Destroyer!!Gimme back my clothes!!Do not grieve,Destroyers can become Battleships!!Don't give up on your dreams!
Move forward!!T-Thank you! Na...
Ms. Mysterious Big Seven Mask!!