I think this is absolutely correct. After mandrew's post, I did some digging around, and can find nowhere where Qualcomm is making a 768MHz Snapdragon for sale to anyone. In fact, the only thing I could find was some speculation on a blog (same site that mandrew pulled his post from) that Qualcomm might sell snapdragon chips that fail to hold 1GHz during stability testing, at 768MHz to handset manufacturers at a discount. No source or link. Even if true, I doubt that Verizon would use a chip that has already failed to perform as originally spec'd, and thus proven to be defective, as the engine of their new flagship phone, notwithstanding what Acer may or may not have done.
Qualcomm does not list a 768MHz snapdragon on their product spec page. Notice that the above says 1GHz Processor? What is interesting is that for the 8x72, they used language that says "up to 1.5GHz." It's a fine distinction, but if they offered the 8x50 in other speeds, it would likely be worded the same, since the specs are listed on the same page. As Mykpfsu pointed out earlier, what's the model number for this supposed 768MHz chip?
All of the above being said, nothing would prevent a handset manufacturer from slowing down the processor via software for whatever reason. All I'm saying here is, IMHO, that if 768MHz is the final processor speed for this phone, one could most certainly root it, and oc it back to 1GHz.
I think you are spot on.