The editorial changes from the original signed document to the copies that were transmitted to the states did not change the meaning. The document is its meaning, not the details of language or style, and an accurate translation into another language would be the same document.
As a hypothetical, suppose the printers had changed the meaning in some substantive way. Would their version then have been the authoritative one, even though it was not confirmed by the Continental Congress? Suppose the printer had inserted the word "not" in some of the copies, sent to some but not all of the states, changing the meaning from declaring independence to not declaring independence. Would the states that got the "not" have remained subject to Britain while the others were independent? Nonsense. The authoritative act was the voice vote to declare independence on July 2, not the signed document, which was evidence of the act, not the act itself.
First use of the name "United States of America" in any style of capitalization appears to be in a series of articles in the Virginia Gazette, published in Williamsburg, beginning in March, 1776:
“What a prodigious sum for the united states of America to give up for the sake of a peace, that, very probably, itself would be one of the greatest misfortunes!” – A PLANTERSo who is A PLANTER?
Likely candidates could be well-known Virginians, like Richard Henry Lee, Patrick Henry, or Thomas Jefferson. But it could have been someone else.
The author was aware of the historical significance of introducing the new name:
“Many to whom this language is new, may, at first, be startled at the name of an independent Republick, [and think that] the expenses of maintaining a long and important war will exceed the disadvantages of submitting to some partial and mutilated accommodation. But let these persons point out to you any other alternative than independence or submission. For it is impossible for us to make any other concessions without yielding to the whole of their demands.”Perhaps some future historian will discover the author.