The article wasn’t clear, but I interpret it as the pastor being loyal to PCUSA. I think he’s leaving because a clear majority (although not the required 2/3) of his congregation want to be with PCA.
Yes, it’s hard to decipher the correctness. Since he seems to have wanted a “vote for gracious dismissal,” I took that language to mean he was disappointed that the desired result fell short of approval.
Actually, nearly but not quite two-thirds (8 votes short) voted to leave the PCA --therefore, although a majority voted to leave, it takes a 2/3 super-majority under their by-laws. He's leaving that congregation because he is personally leaving the PCA and his congregation is not.