The Bug
The powered rail or activator rail updating sequence is reverse of that of earlier versions. More specifically, while rails in 1.18(or earlier) update in a sequence opposite of its sequence of being powered, they now update in the same order as that of its powered order. A more vivid description of this change can be seen in this video Minecraft News: 22w11a Mangrove Roots Are Insane - YouTube by ilmango, starting from 20:10.
Steps to Reproduce
This is easy.
Build a chain of observers with its 'face' facing upward and 'power' downward.
Place a series of powered rail (or, alternatively, activator rail but with same type throughout)
Place some power indicators (like redstone lamps) underneath each observer.
Use a power source to power the rails, and observe the lamps.
Redstone Lamps may not be as conspicuous. It's recommended to use an item conveyor chain consisting of droppers with comparators as indicators.
The behavior should be different across versions.
This bug has devastative impact on many old redstone mechanisms that rely on the update sequence of rails. If the change is unintentional, please fix it.
Comments 4
It is slightly more intuitive. But older player structures are more important in my eyes. It is more than structures.
Design patterns have evolved around this specific mechanic. One of the most commonly used instant lines for example just broke.
There are entire CPUs build on update order. This is all to make Redstone a tiny bit more intuitive for new players.
If the devs however disagree I'm also open for change.
But that should also mean that Redstone update order should get fixed to make it more intuitive and increase its performance.
I always like when redstone changes in a way that can help more people to understand it. Currently this is pretty much a "Change this because it will break old structures" situation.
I have seen Ilmango's video, and definitely seeing the new behavior I'm pretty happy with it. I'm not the best at redstone and this is useful to get easier systems for non technical players. Redstone behaving more logically opens the possibility for getting more players using redstone, and building potential new contraptions.
I think the change they made should not be fixed. If old redstone builds breaks is up to you to fix. Mojang can't forever support old behaviors (some even can count as a bug).
I didn't know about the update order and have always assume it updated from where you trigger observer's or pull a lever.
So fix the redstone dust update order also.
This is (kind of) more intuitive for non-technical players though, which makes redstone available for more people. Also, older player-made structures are always subject to break on any game as long as updates go on, sometimes it's just that we need to update our structures.