Nobody said (certainly not the Dems) that the three judges for whom cloture will be voted are not extreme in every sense of the word. The Dems agreed to cloture for these three nutters in exchange for taking the nuke option off the table for this term of Congress. It sets no precedent whatsoever for who is deemed extreme, or what is an extraordinary circumstance, and certainly does not close the door to ideology being used as an extraordinary circumstance
I don't agree with your lawyer-like analysis of things. This is based on a good faith understanding. It is not enforceable in court, by the senate parliamentarian, or anywhere else... so hyper-technical readings are of little import. If the Pubbies feel the Dems are not living up to the spirit of the deal reached, then we're right back to square one. Lindsey Graham, a signatory, has already made that quite clear.