I think the unfortunate aspect to the debate about maps and men is that one can believe the premise that there is some generalizable basis for how States/Nations/Federation/Union are formed and moved. One theory in anthropological circles goes primarily towards one thing: power (see Michel Foucault). In effect, actions that would change boundaries come as expressions to control others in order to exact what one wants (‘national security interest’ is a nice catch-phrase). Hence, centuries have shown nations/countries/bounded areas ebb and flow in design over time as the powerful controller’s prominence rises and fades.
I would add to that a more traditional view of what might drive political bodies to develop changes in formal boundaries: requirements for resources. I would argue these all intertwine to create drivers that end up changing boundaries through actions, such as war or, in prior times, political marriages. I suspect if we look at the post-Roman empire landscape, the landscape across their empire shifted in regional forms over the centuries–degrees, maybe, based more/less on the extant characteristics of the inhabitants in the locale. I think that is effectively where we are now with the Middle East. If we step back and view the landscape from a millennia time frame, the shifting will probably show many changes that make it seem continuously in flux. A few decades view, probably makes things seems like the the ebbs and flows are something quite different.
In thinking about laying the odds of how the ME landscape could be moving forward over, say, the next 50 years: I would begin with the notion of exerting power from a narrow in group focus (i.e., extended families and/or tribes) and then expand from there to peoples with of common cultural elements (ancestry, religion, affiliations) that would provide the ability to exert power to ensure safety and control resources (and in Gaza/West Bank case seem like humans with freedom). If external entities stay out of the way in drawing lines, and allow the area to organically shift, I suspect the 50 year view would be one of constant change along those dimensions, and I suspect Israel, Syria, and Iraq to be three locales that have the best chance (almost certainty) of different boundaries being created.
These are just some thoughts at the moment, and sorry if I’ve rambled. I only hope I’ve added something, even if small, to the conversation.