What is the explanation of the Hadith: "I was sent, and the noble character traits are like these two," and does it mean that noble character traits will come into being a short time after Muhammad?

The aforementioned Hadith was not narrated in the form mentioned in the question. It seems to be a combination of two Hadiths: The first, narrated by Anas in the Two Sahihs, indicates the proximity of the Hour to the advent of the Prophet, peace be upon him. The second, narrated by Al-Bayhaqi and others from Abu Hurairah, states that the Prophet, peace be upon him, was sent to perfect noble character. This religion is a religion of high morals and sublime values, as one realizes the loftiness of his character and the excellence of his dealings with people and his upbringing of his companions and his Ummah.