Marsh areas do not generate in swamp biomes

Still affects 1.13.0.2 beta

Of course I checked first if it is intended, but I wasn’t able to find any sources of they where removed, I checked almost all changelogs. So It is most likely a bug. Because they always say If they remove something in the changelog.

Steps to Reproduce
1 enter the seed 1411648432
2 teleport to
x: 183
y: 63
z: 0

Observed result:
No flat terrain with puddles within swamp

Expected result:
In the swamp, there are some areas with flat terrain.
As I am an IOS player, I can not check older versions of the game, but I know that in 1.0 the puddles already were absent. So at least the bug affects 1.0 onward
As well I can’t not take any photos of the earlier swamp terrain, so I have to copy photos from the internet.