These domains aren't being seized, they are being blocked. In this case, as per TFA, they're just overriding the domain nameserver at the ISP default DNS server.
Even if they were actually seized, do you think if the police seize a rental car they'll be paying the rental fee until they give it back?
Seizing a domain probably costs way more in procedures than any renewal fees.
Also, blocking websites typically doesn't involve ICANN, the infringing website still owns the domain. They just order ISPs in the country to lie on some DNS queries, which is the reason why such blocks are so easy to work around.
- create a vanity TLD with high renewal fees
- register a bunch of sites that are mirrors of already seized domains
- mention them in enough places they get noticed
- ???
- profit