It's tradition by now that new ship/abyssal pairs will be drawn by the same artist.
I don't think that's always the case. Watanabe Akio skipped on Matsu and Take's abyssal designs as both were covered by Shibafu. Style-wise, this one definitely looks closer to Hoshiakari's than it is to Ugume's, especially the facial features.
Note: I think it was confirmed by the artbook that I-47's abyssal counterpart was indeed drawn by Hoshiakari. Compare this and that and you'll see similarities.