I would go with keeping the Ars name since this is the name used in the wiki years before the official translation is released out of respect for the previous contributors for the wiki. So for what Forthicy changed, I will most likely revert it and just add redirects of the official names to their articles which is the same thing that happened last time when I have the time
https://mantan-web.jp/article/20220201dog00m200058000c.html:
Translation
It turned out that the cumulative circulation of the popular light novel "Mushoku Tensei: Isekai Ittara Honki Dasu" (KADOKAWA) has exceeded 10 million copies. About eight years after the publication of light novels started in January 2014, it has exceeded the 10 million mark. "Mushoku Tensei" is a light novel born from the novel posting site "Let's become a novelist". A 34-year-old unemployed man is driven out of his house and is run over by a truck and dies, but he is reborn in a different world of swords and magic, and with the intelligence and regrets of his previous life, a new life begins to move.
The Light novels have been published up to Volume 25, comicalize up to Volume 16, and spin-off comics have also been developed. The first course of TV animation was broadcast from January to March 2021, and the second course was broadcast from October to December.