@lpetrich:
The theory isn't really new. I've engaged into just that kind of speculation before, before discovering that Josephus beat me to it by nearly 2000 years.
The problem with that is that it's rather unsupported, and often counter-factual. Ain't that usually the case when pulling stuff out of the ass to fit a story?
E.g., the problem with the Thera eruption is that it's at the wrong time AND in the wrong direction to explain the Exodus as the Hyksos marching in the direction of the plume.
1. The explosion happened in mid-17 century BCE, but that's when the Hyksos INVASION happened, not their expulsion. The expulsion, as you note, happened about a century later. The notion that there would still be a plume for them to follow, to explain the Bible narrative, is simply nonsense.
2. If you actually look at a map, it's in the awfully wrong direction too.
Basically if there's any connection with the Hyksos, that would be with their coming INTO Egypt, not their going OUT of it.
Mind you, even the invasion still is actually about 20 years off the mark for Thera, but who's counting when we're at just making BS up to rationalize the Bible, right?
And that's just the beginning of the problems.
E.g., there is no record to say they were going through any marsh, and in fact everything we do have points at a chase through northern Sinai and into southern Canaan. So inventing a marsh to rationalize the bible account is just that: it's just inventing stuff, not doing history.
E.g., for all we know, the escaping Hyksos were a small enough army to take just one city and hastily fortify it, but then that city is taken and razed by Ahmose and then they just disappear from history. We don't hear about some big migratory host waging war across Canaaan and taking cities left and right.
Which kinda we should have, since that was a major trade route between very literate provinces, and soon thereafter would be invaded by Egypt.
Also, if it were the Hyksos that conquered half of Canaan there, that would have happened between 1550 BCE and the Amarna letters around 1350 BCE. So we kinda should find some mention about some mighty Jewish kingdom there that the Egyptians either conquered or ran into problems with or was attacking its new vassals or such. But there seems to be nothing there to fit that description.
The more damning part is that the Bible itself doesn't support that. Jerusalem for example was conquered by the Egyptians in that period, and far from being ruled by followers of Joshua and that gang, it was ruled by client-kings appointed by the Egyptians. You'd think that getting absorbed back into Egypt would be a major event for a religion whose main claim is that their God got them out of Egypt, but there is nothing in the OT describing anything like that after the Exodus. Which is weird, because they have no problems including stuff like their later being rolled over by the Assyrians. So if their history starts actually in 1550 BCE, how did they miss a much more important event?
Etc.