No more Ironic than Abraham Lincoln citing the event of Independence (four score and seven years ago = 1776) after a just concluded battle to prevent it.
Jefferson's point remains. You do not wring new meanings from the text, you follow original intent.
It’s not ironic or analogous. The slavocrisy may have had the prerogative to revolt, but they didn’t have the moral righteousness of their cause. Lincoln understood and respected the original text and the original intent where the south did not: you don’t rebel unless you have a damn good reason. The south didn’t have one.