Maybe we will start seeing M4A4 choices more often as of now. The other change is really bad news for AWPers as they will need to use their bullets more effectively from now on.
If the damage remains, it is not much of a nerf for good awpers. They just need one bullet to kill a player, and it is seldom that they need to fire two consecutive rounds. If rushed, most AWPers use their handguns. 5 bullets per clip is more than enough, especially for Pro.
Puppey and his teammates will adjust easily like how they've adjusted so quick during the LCQ.
As for Nisha, not yet confirmed that he'll play for Team Liquid but we have that feeling that his choice to leave Team Secret, he's going to another strong team that he know of to sign him we just have to wait for further official announcement.
They did well in Riyadh when Reso was still a substitute that is why when he becomes an official member, I know they will do really great. And it proved to be true, they finished 2nd in TI with that roster even though they were just formed two months before LCQ. Sometimes, you just need that one person that will complete the team even though they are joining in a short time before a big competition. For Team Secret, it was Reso.
I think you are right. I do not think Puppey would let go of Nisha if he does not have another team to go to. Let us wait for any team that will announce where Nisha would go. I know he is a good asset and a team would likely pick him up soon.