I wish I understood the question.
Me too! I couldn't get my head around the phrase "atheism (et al)" - I assume it means "and the other things mentioned in the OP" - namely,
theism? Agnosticism? Apatheism? Ignoticism? Transtheism?
Well, if we go back to the originator of the term "theism", Ralph Cudworth, he defined the idea thus: "[they are]
strictly and properly called Theists, who affirm, that a perfectly conscious understanding being, or mind, existing of itself from eternity, was the cause of all other things" - to me that very clearly is a worldview because any and all other knowledge and perceptions of the world that a "theist" may come up against are interpreted in terms of that idea. I.e. for a theist, the idea of theism explains both the existence and the continuing 'evolution' of 'the world' and therefore it is a 'worldview'.
However, atheism - which basically means that such a "being or mind" or "beings" or "minds" are not necessary to explain the world and probably (or definitely depending on how strong you like your atheism) don't exist at all. That's not a worldview because it explains nothing at all except itself (if you see what I mean)...though I can't help but wonder at how come such a simple and self-explanatory term generates so much debate regarding its own definition.
Ag/ignosticism either don't know or can't know whether there's a deity or not and apatheism couldn't care less...so none of these can be worldviews because they don't hold any explanation of any facts about the world except that some possible facts are unknown or unknowable.
And I have no idea what "transtheism" is so I have no idea whether it is a worldview.
There are others - deism - the idea there is/was a creator who takes no further part in the unfolding of reality after the moment of creation is probably a partial "worldview" in that it explains the existence of the world but not so much about what subsequently happens in it.
Pantheism/pandeism and panentheism seem to me to be (at least partial) worldviews because they have it that the entire world is equal to or part of deity and therefore any facts or perceptions about the world would be interpreted as such. But I could be wrong about that - there are probably as many versions of pantheism (etc) as there are pantheists (etc) so some might be more of a worldview than others I guess.
So atheism - no, not a worldview - et al - some yes, some no, some maybe or partial...more or less..."you pays your money and you takes your choice".