When Paul said “Inheriting the world” (Rom 4:13) did he universalize the Abrahamic blessing? Yes and no.
I have read and heard commentators (e.g. Tom Wright – but many more) who think that Paul’s statement in Romans 4:13 means that the Land promise to Israel has been universalized to the exclusion of the concrete promise to biblical Israel:
It was not through the law that Abraham and his offspring received the promise that he would be heir of the world, but through the righteousness that comes by faith.
Did Paul universalize the Land Promise? No, if by that you mean he revised the promise. Paul was not the first or the only Jew to think in universal ways about the promise. Consider this text from Ben Sira 44:21:
Therefore, the Lord certified for Abraham with a solemn pledge that he would bless nations through his descendants, that he would make him increase like the dust of the earth, exalt his descendants like the stars, and give them an inheritance from sea to sea and from the river to the end of the earth.
Indeed a number of Second Temple Jewish writers thought universally about the Arahamic promise as Ben Sira. I think this had to do with the conflation of Davidic and Abrahamic traditions. That is, the universal imagination related to the Davidic promise meant the expansion of the Abrahamic promise to include all the realm of David’s kingdom, which would come to include “sea to sea” (Psa 72) .
But what is not necessary, and indeed should not be we concluded from this, is that the writer of Ben Sira or the Jewish Paul for that matter had revised the Land promise to the degree that it no longer had a concrete reference to Eretz Israel. Certainly Ben Sira in his universalization of the Abrahamic promise did not also mean to say that the redemption of Eretz Israel was no longer part of the eschatological intentions of God.