I didn't see that part of the post, but it didn't explain why Nigeria is excluded since casinos and gambling are allowed in Nigeria. The website is not being truthful.
This is a bit strange indeed and if I'm not mistaken this is the only online casino that restrict Nigeria, at least this is the first one I know of! Their explanation that they need to comply with laws and regulations doesn't make sense since gambling is not prohibited in Nigeria.
I don't know if there's restriction towards usage of crypto in nigeria so maybe there's something related issue in terms in legal matters that's why they decide to restrict that country in their casino. But so far upon searching online casino is legal as long as it is regulated by their government.
Vbet management could give an accurate answer with this inquiries since for sure many nigerians are also wondering about this restrictions.