As an example Calgary's playtest is coming up in 2ish weeks. Changing the packet is not something we want to do repeatedly as chapters are preparing their players for these events. Chapters are allowed to run multiple playtests as well, so check with your Chapter Owner to see if they are up for running more.
My thoughts are this. A single weekend playtest will help players a lot. A second weekend playtest will be even better as players will become more familiar with the changes and it won't seem so "abrupt".
And, please note, lots of the things that have been discussed (I'm looking at you Riposte Strike!) have had the owners, and ARC, fine tuning them and there should be a FAQ and clarifications on some of the items coming out ASAP. Not sure if they are going to release an 11b or not, that is up to ARC.
As for the theorycrafting, sure, it is needed. But until we actually get to test them, some of it is more speculative and "what ifs" than based on testing. That is why we need to test. We can find out if skill A is working as intended, or Spell Z is to OP and needs to be toned down etc. Just piling more things in on top of what we already have just because we thought it may go one way could lead to a lot of unnecessary work. The owners, and ARC, are very aware that we will have to review each and every piece of .11 to see what needs to be addressed. At that point, all options are on the table to tweak things and player's theorycrafting is very much reviewed.