>I doubt these are made by the same company, they are lighter >than the Nikon MB-D11.
Maybe because they're plastic and not metal. Using one doesn't preclude the maker from using the other.
>Has anyone had a verified case of warranty being denied >because of a 3rd party battery, lens or grip was used?
I never claimed it had. Perhaps if someone had a problem with their camera and sent it to Nikon, replete with 3-party grip installed, there might be an issue. But I don't work at repair facilities for a living, so I can't speak to it.
I hate when people ask me what I see myself doing in 5 years...... I don't have 2020 vision!