I looked at this some more, and that theme runs from 2:104 to 2:112.
Haani Taahir, in his book تنزيه آي القرآن عن النسخ والنقصان, pages 22-25, suggests that the theme is actually part of a larger theme about the Jews, that runs from 2:40 to 2:123. He's right. In fact, I see that the theme about the Jews is covered in even more verses in Chapter 2.
He cites Al-Ghazaali from his book نظرات في القرآن, pages 244-248, proving that the context is clearly about the Jews objecting to the Quran abrogating the Old Testament. He asks why they found that objectionable when there is confirmation in the Old Testament that God will take from Judah a new testament (Jeremiah 31:31-32).
Indeed, God tells us in the Quran that not only did the Jews know that there will be new revelation, but that it will be given to other people,
{6:89} Those are the ones to whom We gave the Book, authority and prophethood. But if these deny it, then We have entrusted it to a folk who are not therein disbelievers. And they also knew the detailed description of Prophet Muhammad, peace be upon him,
And they knew that the only Qibla is Mecca,
But they simply concealed that knowledge, because, obviously, it robs them of privilege.
Al-Ghazaali, as well as Jamaal-ud-Deen Al-Qaasimi in his exegesis, stated that this interpretation, that the Quran is the new Sign, also applies to 16:101. There, the polytheists wanted a physical sign to impress them. Al-Qaasimi says that this is evident by the verse that comes two verses later, 16:103
Al-Qaasimi, Mustafa Zayd and Sayyid Qutb all said that the same interpretation also applies to 13:39, evidenced by the preceding verse 13:38,
Thus, Taahir concludes, that all the verses that scholars used to prove the abrogation doctrine, all mean that the Sign of the Quran replaces prior Signs from God.