Video with a relevant timestamp:
It will be interesting to see if Blizzard mentions anything about this interaction, as it was assumed by most of the community that this interaction was most likely not going to work in Classic. The difference between how this functions on Pservers vs Classic is that on Pservers you just had to be sitting and the guaranteed crit against you would proc your reactive talents, but in the Beta you need to be getting up from sitting when you are hit to both be crit (from having been sitting) and then the reactive talent will proc because you are now standing.
Blizzard EntertainmentIt's an exploit/bug.
As we’ve discussed before, the nature of WoW Classic sometimes invokes different memories for different players, and this leads to certain misconceptions for some about what is or isn’t working as intended.
The following is a list of commonly-reported gameplay in WoW Classic that is not actually a bug, and is working as we expect it to:
Being critically struck while using /sit to sit does not cause abilities like Enrage, Blood Craze, and Reckoning to activate.
Yeh it seems to be part of batching, even though earlier in the video he said it wasn't. If there is a 'batch' of commands that happens within a set window of say 100ms, you can be both sitting and standing in that batch, meaning that if it happens in the right frame of time, you are crit for sitting, but proc reactive abilities from being crit while standing.
Interesting, not sure how/if they will fix this.