As The Verge reports, your ISP can still charge for a router sent to a customer, but that customer should be able to return the router, have the fee canceled, and supply their own router instead. The charge is typically $10 a month, so the cost of buying a router is soon recouped. A good budget router can cost less than $50, meaning you'll start seeing the benefit of money saved in less than six months.
Don't expect ISPs to take the initiative here and cancel the fee automatically. If you are already using your own equipment, contact your ISP and demand that the fee is stopped. Send them a link to the bill if they protest. Alternatively, if you are using the equipment supplied by your ISP, do some research, see if there's a good alternative available and check the process for returning the ISP-provided equipment before attempting to cancel the fee. You want to avoid any internet downtime, especially as we are all so reliant on the internet for communication right now.