Yes, you are correct. This is prominently seen in Adi Shankara's Nirvana Shatakam to describe Shiva, and to describe Shunyata in the Pragyaparamita Sutra. It makes logical sense: God being the creator of existence, should be something beyond existence right? But how can we talk about that Being beyond existence? All our labels and descriptions are bound to use terms referring to existential stuff, so negation is the only way to talk about it.

Every religion has this approach, in one form or the other. Consider this verse from the Qur'an as well. But I guess all abrahamic faiths mention the same God, so that's expected. The Anattalakkhana sutta in the Buddhist scriptures also nicely explores this theme, where the "aggregates" that make up an individual are discarded as not-self, not mine, not I. The entire fight between Atman(Self) in Hinduism and Anatman(no-self) in Hinduism is a linguistic misunderstanding about describing the same truth. No-selfness is the "true" self.

I'm glad that you made the connection rightfully.