Gowest website still lists packages with Nos Krusero though I don't see where "affiliation" matters unless you're getting a discounted price. Stay anywhere, dive with anyone.
Nos Krusero is still listed by Go West but if you try to book there is only All West listed. Also, Go West is not listed on Nos Krusero’s site for packages. Ultimately, you’re right Stay anywhere, dive with anyone. Some people look for the package deals, though, so I was just pointing that out. If I went for strictly a dive trip, Nos would be a consideration.