At LAX my checkin agent didn't know the temp visa waiver and she was looking for a visa, and then I told her no visa between 6/1-9/18 for US, Canada, Australia, Japan passport holders, and she was able to check me in LAX-GRU flight immediately. That was 6/2.
At GRU the immigration officer didn't know the temp visa waiver and she kept asking me about visa in Portuguese (I believe).
My friend got 10 years visa last year, so he didn't have any problems even he didn't need it then.
She went to talk to a different officer and finally she found out the visa waiver.
I had to wait for good 15 minutes standing there