Yes, it’s legal for you to use a VPN to securely access Kocowa. We know no reported cases of individuals facing prosecution for accessing US TV services abroad.
However, many US TV providers explicitly state in their Terms of Service that using a VPN to bypass region locks is prohibited. This is why services like Kocowa actively block as many VPNs as possible.
Streaming services like Kocowa want to keep collecting subscription fees. They focus more on blocking VPNs rather than individual user accounts.