Expected (How it works in LoD):
- Weapon switching only possible while in idle, moving or hit recovery animations- not attacking or casting
- Weapon switching interrupts current animation and sets you to idle, allowing you to immediately move/attack/cast on that same frame
- Weapon switching makes you appear to stop moving briefly to other players as seen on their clients, desynchronizing your movement to make you appear to fidget-in-place-between-updated-positions if spammed rapidly while moving without interruption.
Actual (How it works in D2R, beta version):
- Weapon switching only possible while in idle, moving or hit recovery animations- not attacking or casting
- Weapon switching does not interrupt hit recovery animations
- Weapon switching does not desynchronize movement.
This functional change from LoD completely wrecks a huge portion of the PvP dueling metagame: Players relied upon weapon switching as a critical utility to balance matchups where players have spells that can otherwise indefinitely chain someone in hit recovery animations (most notably, mind blast and leap). Without the ability to interrupt hit recovery animations, dueling games get ruined by permastunning builds. This was briefly the case a few years ago during patch 1.14, when the classic games team changed how weapon switching worked on serverside. After some outcry from the players, they more or less restored the functionality a month later.
Its possible that D2R was built using that older version of the code that hadn’t yet restored weapon switching functionality, or its possible someone mistook this as a glitch that needed fixing. Either way, this is a big change from the original Diablo II functionality and would create a completely different (and unplayable) PvP metagame. Without this option, people can just walk into blood moor with a barbarian with high level leap and lock everyone else up indefinitely by spamming it nonstop.
Here are video examples of the difference between D2r and LoD, provided by user DHA:
Lord of Destruction: d2 Wsg comparison - YouTube
Resurrected: D2R Wsg Not Working - YouTube