My first thought was "Life has no inherent meaning" is more apt than "Life is meaningless." The latter is a sub-set of "life has no inherent meaning", which is apathetic-nihilism. The term ‘meaningless’ is somewhat a floating signifier in the general purpose use. It may be useful to you to include the sub-categories of nihilist thought.

Someone could identify with "Moral Nihilism", yet not "Existential Nihilism; focusing on how morality and religion are subjective constructs, yet they could accept biological imperative as humanity's raison d'etre.

I think there is a confusion between material reductionism and nihilism that may be worth mentioning. As some nihilistic thought posits we enact with generally agreed upon external reality (eg. interest of self-preservation) yet some nihilists may acknowledge how a mnority of people who chose to be self-destructive signify other impulses. Thinking that people are a product of reacting from biology and neurochemistry is not necessarily Nihilism.

An Existential Nihilist could adopt less materialistic explanations when questioning the nature of existence. It can be argued that materialistic interpretations are just as much social constructs.

A General Nihilist accepts most or all Nihilistic subsets (which I think that's what you're describing?)

For fun I'll mention the common flimsy rebutal thrown at Nihilists:

" Isn’t belief in nothing a belief?” Yet it isn’t, and that is a semantic argument. Belief has faith behind it. Nihilists are adaptable, and malleable in what concepts they adopt. The central thing is always questioning personal beliefs and truths we adopt throughout life; a genuine ('practicing' as I'd say) Nihilist puts their own accepted constructs to the test before anyone elses. "Nihilism ain't easy"

Just throwing some thoughts out there. I think you got it down and apt aside from the misunderstandable 'life is meaningless'.

I think all post-modern cultures are essentially nihilists too. Especially considering how commonly accepted 'cultural relativism' is in the globalist age. Nietszche predicted the conundrum of it; the inability of people/cultures to stand for something due to inherent nature subjectivity.

hell am I looking forward to your post!!!