The whole question of chronologies regarding ancient Egypt and the lands surrounding it are in a state of flux at present. There is good reason to believe that the pyramids are no more than 3000 years old, if that. I would recommend two books by Emmet Sweeney,
The Pyramid Age, and Genesis of Israel and Egypt for anybody interested.
The exodus of the Israelites from Egypt occurred under catastrophic circumstances and not much will be found from the time. The Ipuwer papyrus is thought to describe the exodus, but there isn't much else.
I think to say the chronology of ancient Egypt is in a state of flux is much too strong. Certainly there are those who would revise the standard chronology up and down. Probably the most attention at the moment is being given to proposals put forward by David Rohl. The chronology is not set in concrete and will no doubt be adjusted from time to time.
I don't know anyone who would date the pyramids to 1000BC, but perhaps Sweeney (whom I have not read) does. You've probably seen the guy on TV (whose name escapes me) who believes they are much older, from perhaps 13,000BC with the sphinx older than that.
The Ipuwer Papyrus is a long document lamenting just about every bad thing that can possibly happen. You can read a translation at
http://members.tripod.com/~Raseneb/Ipuwer.htm.
I have yet to read anyone who associates it with the Exodus but I suppose there are some. Hoffmeier, a believer writing to justify the Exodus, quotes Ipuwer but only to show the pharaoh's responsibility to keep order. He makes no claim that Ipuwer is describing the Exodus. His summary statement, after describing the early work in Biblical Archaeology, was:
"But subsequent investigations of these sites reversed earlier interpretations, and the evidence that originally appeared to confirm the stories concerning Israel's origin was met instead by embarrasing silence; for some this implied the repudiation of the Hebrew tradition....Since the pioneering days ...considerably more archaeological data has been uncovered in Egypt, and yet, even as the discipline of archaeology is about to enter a new millenium, direct evidence for the events and figures of Genesis and Exodus remain elusive."