The bug
Coral, coral fan, sea grass(tall) and kelp lacks death variants.
Note
Dead coral fans exist in bedrock editions.
Linked issues
relates to
Attachments
Comments

This is more of a feature request instead of a bug, seems invalid, unless there's supposed to be a dead variant already.
Well, for coral fans it's valid as there's the intention to have all features on both java and bedrock.
But for the others... not sure what to do with that.

Affects 18w21b

Affects 18w22b

Affects 1.13-pre1

Affects 1.13-pre2

Affects 1.13-pre3

Affects 1.13-pre4

Affects 1.13-pre5

Missing parity Java vs. Bedrock is not a bug.
Fixed for coral in 1.13-pre8 :V

Fixed for coral fans in 1.13-pre8.
Still an issue for coral in 1.13-pre8.

There is no dead coral in BE
Actually, in Bedrock Edition, there's dead variant for coral fan.