The Nation of Israel is an end-times figure in certain end-times teachings... So if Jeshrun is another name for Israel, that makes Jeshrun an end-times figure.
The short version is as follows:
This is tied to Dispensationalism, and certain premillennial views. The short version is that we are currently living in the "Church Age" which is a brief respite in the Seventy weeks of Daniel. This is a time period here God's dealings with Israel is suspended. In the pre-tribulation rapture view, the Church will be raptured, which will signl the start of the seven year Great Tribulation, in which God will again be dealing directly with Israel. Those seven years represent the final "week" in the seventy weeks of Daniel.
References for further study:
Why do some people consider Jeshurun to be an end-times figure?
The usual disclaimer, I'm just outlining the beliefs. Not everyone agrees with these views.