Better buy back/offer refunds to those who purchased the products. I can see charging a subscription going forward and grandfathering in existing customers for free, but are you legally allowed to modify a product after purchase?
If I bought new vehicle with CarPlay advertised and then a year later had to pay $4.99 every 30 days to keep a feature that my car was advertised with, then they lied when I bought it.
I see a class action coming on. Deliberately making a product with a free service and then making it compulsory to charge that service to make the product work!