>Since minor changes can affect the meaning of these agreements, they are only edited or amended in the software in which they were originally created.
How much difference can switching from word 2007 to word 2016 be? Even switching between microsoft office and libre office, the only thing that would get mangled is the formatting, not the text itself.
I can imagine (badly-drafted) agreements where things are specified by page number or level-of-indentedness, like "Until the major conditions listed below are met, the government will supply the items listed on Page Y." If those references were inserted manually, any formatting changes could have unintended consequences. If they're done automatically (with SmartText), they might break in other software.
I would guess it's mostly paranoia--you'd have a hard time convincing a judge that the one orphan item that spilled over onto page Y+1 wasn't meant to be included--but I can sorta see not wanting to risk it.
How much difference can switching from word 2007 to word 2016 be? Even switching between microsoft office and libre office, the only thing that would get mangled is the formatting, not the text itself.