The Minchas Elozor (Munkatcher Rebbe, also a famous mohel) quotes a number of sources who posit that although we find people who are born somewhat circumcised, nobody today is born completely circumcised. He does, however, bring conflicting reports. [See link for further definition; see also Avnei Nezer YD 334.7]
R' Yisroel Belsky reported having officiated ...
I once asked this question of a very famous mohel. He said the people you listed were born mohul. However, no one nowadays is born that way. There may be just a little skin, but everyone has something and needs a bris.
In Sefer Hamidos it states:
ה. מִי שֶׁנּוֹלַד מָהוּל, בְּיָדוּעַ שֶׁכּחַ הַמְדַמֶּה שֶׁלּוֹ טוֹב
One who is born circumcised, it is certain that his power of imagination is good and proper.
Sorry, I do not know of any recent Tzaddikim who were born circumcised.
Here is an excerpt from Encyclopedia Halachit Refuit from Dr. Avraham Steinberg.
Translation (my own): A women who underwent surgery to appear like a man, even if they formed for her a male limb, there is no obligation to do a bris on this limb, even if it is formed from her natural clitoris.
In regards to a non-jewish woman that underwent gender ...
Circumcision is a symbol marking the covenant God has with his people. But as God is interested not only in people's bodies, but also their minds, hearts, desires, souls, etc, so God's covenant concerns not only physical acts but also what is in our minds and hearts:
Deuteronomy 6:4-6 (Judaica)
Hear, O Israel: The Lord is our God; the Lord is one.
Circumcising the heart is the example given by Ibn Ezra in his commentary to Exodus 20:1 of a commandment that doesn't seem to make sense:
וחלילה חלילה שתהיה מצוה אחת מהן מכחשת שקול הדעת רק אנחנו חייבים לשמור כל אשר צונו השם בין שנגלה לנו הסוד בין שלא נגלה ואם מצאנו אחת מהן מכחשת שקול הדעת אינו נכון שנאמין בו כי הוא כמשמעו רק בספרי חכמינו ז"ל נבקש מה טעמו ...
This is the subject of the fourth discourse of the the Alter Rebbe in the fourth section of the Tanya called Igeret HaKodesh.
He explains that process of circumcising the heart is to remove ones material desires through the process of teshuvah to the extent that it reveals the true nature of the innermost essence of ones heart. That at the core of ones ...