I am just curious: why the author wrote “Word”? Was John trying to point us to the book of Genesis where God said “let there be…..”
If the writer doesn’t tell us why then we can only guess. But if he uses the same word in another context then at least we may be able to make an educated guess. In 1 John 1, he referred to Jesus as “the Word of Life” and in that context, framed him as someone that he wants to proclaim.
“That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked at and our hands have touched—this we proclaim concerning the Word of life. The life appeared; we have seen it and testify to it, and we proclaim to you the eternal life, which was with the Father and has appeared to us. We proclaim to you what we have seen and heard, so that you also may have fellowship with us.”
So, in his use in 1 John, Word conveys message, the medium to convey truth and purpose.
In John 1, the writer wants to differentiate Jesus from God and yet bring them together as one. So he used “Word” as the entity that conveys truth and purpose.
You are right, in that “In the beginning” brings us to Genesis 1. Perhaps in the phrase “And God said” (meaning that he spoke a word) John could bring Word as close to God as possible. Here, Word could convey purpose, as in God spoke a word that conveys his will.
I hope that helps.