Confirmed in 1.21.11 and 26.1-snapshot-1.
Confirmed in 1.21.11 pre-release 1.
Confirmed in 25w46a.
Confirmed in 25w45a.
Confirmed in 25w44a.
Confirmed in 25w43a.
Confirmed in 1.21.10 and 25w42a.
Confirmed in 25w37a.
Confirmed in 25w34b.
Confirmed in 25w32a.
Confirmed in 1.21.8 and 25w31a. I have also noticed that the bug is directional: if the water is refilling from the south and the east it will not happen, but from all other directions it will freeze as it is refilling.
Confirmed in 1.21.7. I would also like to request ownership of this bug (I am the original owner before it migrated) so that I can continue updating it.
Confirmed in 1.20.2.
Confirmed in 23w16a.
Yes, I believe it is very related to that bug report/feature. However, if you do the setup as in the picture "Spreads2", the stone with the carpet on it does end up converting to sculk. This doesn't make sense if the stone has to have air above it in order for the sculk to spread normally. For some reason, this particular setup, with the mobs dying on a block directly touching a sculk block, causes this rule to be ignored. Hence the inconsistency.
Confirmed in 23w14a.
Confirmed in 26.1-snapshot-2.