No doubt. Since persons are beings.
Indeed - since God "does not change" God is in a "state of being" vs a state of changing or a state of "becoming".
We are each one beings - but we are all in a state of "Becoming" because we constantly change. God does not change. That is the context for the word "being" that was added to the creed.
hence
And as we just saw in that video - that is exactly the point that was put into the creed.
The mistake you’re making is confusing hypostasis with ousios, and also of using the word person rather than prosopon. God has one ousios, and the word ousios is translated into English via Latin as substance or essence, but directly translated means “being.” God is one ousios (being), with three hypostases and three prosopa. The Greek word prosopon is most accurately translated as face; it originally referred to theater masks, but really, it has the sense of identity and personality, of humaness.
The etymology is that in in classical antiquity, slaves or other undesirables were regarded as “habeas non personam”, which is to say faceless or unrecognizable, in that they had no human rights legally and were not viewed as fellow Greeks viewed other Greeks and as fellow Romans viewed other Romans.
Now for a brief but important segue: our individual existence, which we should not call personhood, but rather manhood or womanhood, because person and people have been expanded in meaning in the service of political correctness for decades (to the point where a friend of mine quit working at one of the Disney parks after 30 years because employees are now prohibited from saying “Ladies and gentlemen, boys and girls” for fear of offending transsexuals, and instead, catering to perversion, the park requires employees to say “People” instead. We should not think of ourselves as persons, but as men and women, because our person historically is just part of us; it is our outwardly recognizable unique identity.
Manhood, as we understand it, is derived from both our prosopon and our hypostasis. We also have an ousios, but everything ontologically speaking has an ousios. When we are dead, our body will still have an ousios. Our ousios however is discrete from, but otherwise undifferentiated from the ousios of every other man, in that it is mutable, beginning as the ousios of an embryo, then ageing, then becoming that of a dead man, and then being resurrected.*
In the case of God, the Son and the Holy Spirit share the ousios of the Father but have discrete hypostases and prosopa. The ousios of the Father is immutable, infinite, eternal, omnipotent, unoriginate, and inscrutable, “a boundless sea of being” and “the ultimate sum of the highest form of all virtues and perfections,” to quote St. Gregory the Theologian and St. Basil of Caesarea. The Son and the Holy Spirit are discrete individuals, each a person with a hypostasis, like how you have been using the word being, but the word being, as I am attempting to show, means something else, and the word that best expresses what you mean by being is hypostasis, which translated literally, means “understanding” but that is not the ideal translation. Hypostasis is a word that expresses such a complex nexus of individuality and existence that I prefer not to even try to translate it. Furthermore, our Lord Jesus Christ actually has two beings, for he is homoousios, or consubstantial, of the same nature, as the Father, and also consubstantial, of the same nature, with humanity. These two beings are united in one hypostasis.
*I also believe we have a soul separate from our bodies in which our hypostases and prosopa will repose in Heaven or experience a foretaste of Hell, and this is an incorporeal state of being, one where I further believe prayers for the dead are efficacious. However, I understand this doctrine is not shared by the SDA, and it is not required for Trinitarian faith.
