It’s very irregular for a country to take back top level domains. Even refusing to renew registrations is unheard of.
ML, tk, etc broke ground by offering free country code TLDs starting 10 years ago. This was possible until Meta sued Freenom this year for issuing domains to the majority of all sources phishing traffic.
Basically, the internet got used to getting TLDs for free, and that was great, except the issuers of said domains (African countries with not a lot of money) have no obligation and no incentive to keep doing that forever. Especially after it became a liability.