Amazing to see this level of detail in a response from blizzard. Honestly I was surprised.
I think option 3 mixed with 1 is a great idea , Allow Penance players to transfer now. Allow Shadowstrike players to transfer to either Crusader strike/Wildgrowth , give them the option to choose the server with the best chance of supporting thier gameplay.
Wildgrowth already has a pretty big OCE population and is on the east coast giving a significantly lower ping. 176ms if i was correct , while Crusader is on west coast and has a significantly higher ping at around 240ms.
Give us the option to choose the lesser of two evils , I think we all respect the effort your making lets tweak it slightly so we get minmal disruptions and also control ques/populations spikes