"Shape: ascending" rails change state to normal (flat on the block) when top rail is removed

Doesn't this specifically break current villager trading hall designs?

Existing rails won't be retroactively changed on upgrade, if that's what you mean.

I was trying to make a trading hall, as the old designs. Since this is a new placed rails, I just can't.
Also, one mistake and you can't service your existing rails (after world upgrade)

never causing an update near your contraptions isnt a fix at all and under certain circumstances reloading the world causes a railupdate on chunkborders therefore even breaking exsisting rail contraptions