I see you've bought the outrage of the day bait. Two minutes hate, if you will.
Anyway, the ISPs could always sell your data. There has never been an enforced law or regulation that stopped them, like any internet company, from selling the data you willingly give them or which passes across their networks.
Some regulations were put into place last year (but never enforced, mind you) that would have prevented ISPs from selling certain data about you. Note that other internet companies, like Facebook, Google, etc. would NOT have been affected by these regulations, this was only a restriction on ISPs.
Congress has essentially decided that the playing field should be level between the Facebooks and Googles and the ISPs. Essentially, keeping the internet functioning the way it has been since its inception and letting the ISPs choose whether or not and what data they will and won't monetize.
Long story short, no rules were "shredded". This is partisan clickbait nonsense being pushed by the media and sites with a political agenda, like Slashdot. So to answer your question, the date at which point they can choose to sell your data is whenever you signed up for internet service, because nothing has ever stopped them from doing this before, and you fell for the bait like most uninformed people.