@Zenon......--Too bad your Prof. did not really answer you. I have Logos Bible Software with 7,000 $ of resources in my Libary since I bought it in 2008 (10 years of spending!).
Your Prof. is correct. It's well attested in the Hebrew bible that Ish-baal was later replaced with Ish-bosheth. I cannot fully reproduce an exhaustive answer here because it would require a short paper. But, the NET Bible translation notes on 2 Samuel 2:8 gives you the answer:
The name Ish-bosheth means in Hebrew “man of shame.” It presupposes an
earlier form such as Ish-baal (“man of the Lord”), with the word
“baal” being used of Israel’s God. But because the Canaanite storm god
was named “Baal,” that part of the name was later replaced with the
Biblical Studies Press, The NET Bible First Edition; Bible. English.
NET Bible.; The NET Bible (Biblical Studies Press, 2005).
I just pulled up " 1 & 2 Samuel: Evangelical Exegetical Commentary " by Harry A. Hoffner Jr. (Lexham Press, 2015).
Hoffner points to the following:
- Hosea 2.16 : " And on that day— a declaration of Yahweh— you will call me, “My husband;” you will no longer call me, “My Baal.”
- Ba'al in ancient Israel could be used in names to not necessarily refer to the Canaanite storm god, but also to Yahweh, since "ba'al" basically means "lord".
- However, due to the idolatry in the northern kingdom of Israel in the reign of Ahab in relation to the Canaanite god ba'al, God demanded ( as quoted in Hosea 2.16 ) through the prophets that Israelites stop calling him ba'al.
- Lastly, it is well-known in scholarship that 1-2 Chronicles is synoptic with 1-2 Samnuel and 1-2 Kings. 1 Chronicles 8.33 and 1 Chronicles 9.39 both reflect the older form of Ishboshet's name.
- The Hebrew and Aramaic Lexicon of the Old Testament (HALOT) also documents this, but I cannot reproduce it here.
In all, there is a lot of textual evidence for this and your Prof. is correct. It is well documented in scholarly resources and the textual arguments are convincing, which is why it's a consensus.