This reminds me of the business practices of the Austrian NIC. Usually domain names expire if you don't renew them. In Austria, unless you explicitly cancel the domain name by fax, they just roll the registration over to the next year and then send you to collections[1] if you don't pay up.
There's no rule that domain names expire unless you renew them, at least for ccTLDs. It's just a convention. Conventions lead to assumptions, and assumptions can be used to scam people.
In general there's two types of businesses: businesses where you pre-pay (e.g. McDonalds), and businesses where you post-pay (e.g. a sit-down restaurant). If you take a conventionally pre-pay service and apply post-pay pricing to it, you have yourself a perfect scam.
[1] https://www.reddit.com/r/sysadmin/comments/1bnjus/the_austri...