Most outlets are not getting this story right. They don't understand the technical details behind what can be tracked, sold, or how your ISP (Internet Service Provider) can advertise to you.
What is changing?
Actually, nothing. The Obama-era rule did not go into effect, but ISPs may have stopped efforts to sell this data due to the new FCC regulation. I would like to think ISPs are nervous about making their customers angry, and realize they could face backlash if they sell your data. That means that all of this is already true, yet you don't get this type of advertising right now (as far as you know).
Note that this also applies to your mobile data carrier anytime you use the Internet on your smartphone (not over wifi, though whatever wifi network you are connected to cannot be trusted either). However, mobile carriers may be subject to different (older) regulations since they are a "telephone" company. I am a computer nerd, not a telecommunications lawyer.
What can my ISP track about me?