Apparently - I haven't tried this yet - a really large portion of the East is blocked off. It's speculated it will be filled in with DLC.
While I am not going to forthrightly claim you are incorrect there is a solid reason for that. After the chip and it's company got moved to Fort Hill following the MQ I had to make way there, however after an hour of running adjacent to these invisible walls all along the eastern bloc of the map I eventually came to the conclusion that like the internal DC ruins - with the Metro system - there had to be an indirect way, there was: Cottonwood Cove.
This is exactly the same as FO3, they do not want you to wander
too easily across the landscape because in doing so - take FO3 for example - you completely ignore all the effort that went into the Metro system. Anyway, it'd be a rubbish DC ruins if you could walk from the Western edge of DC ruins right up to Reilly's Rangers Station.
Other than the whole eastern wall having a barrier, I don't know the purpose of this thread. FO3 had these barriers, albeit they used large scale rubble to induce the thought that you are
not meant to just walk over it but rather under it via the Metro. If you could simply walk amicably from the Eastern edge of The Strip directly to Fort Hill it'd be pretty daft. And if you pay attention to the close details the game reveals, people
know Caesar owns the entire Eastern bloc of NV. An example, look at the blockade the NCR have on the Dam shutting out the East side.
The balance between MQ and exploration is difficult because in FO3 you could skip about 3/4 MQ ahead by
exploring which effectively creates a large hole in the plot. While at first I was frustrated at jumping, with some awful animations, to the top of boulders only to be barricaded off I felt relieved in going to the Cove as per the MQ. The one qualm I have is that if you make a marker anywhere in the Eastern bloc it does not detour you to Cottonwood Cove to access that area. Just like when you marked an Internal DC zone it showed the various Metro detours you had to take to get there.
Reno