On a very slightly less paranoid note, it’s more likely to be as a result of the Investigatory Powers Act of 2016 obliging ISPs to track site visits. They can’t look at what you’re doing without a court order, but they are obliged to keep a record of where you’ve been for up to 12 months.
The idea of locking down DNS settings seemed to take off about the same time and logging DNS lookups would be one way of doing it.
