The 18-CD edition of The Cutting Edge also contains a version of this final take without the lead guitar played by Wayne Moss; this version is maybe another half second longer than the mix with the guitar added.  On page 169 of his 2018 book That Thin, Wild Mercury Sound,  Daryl Sanders says:

Like all the other musicians interviewed for this book, Moss insists there was not any overdubbing on the Blonde on Blonde sessions, and that included “I Want You.”

However, if Moss's lead guitar was recorded on the four-track master at the same time as the other instruments, it's hard to understand why the producers of The Cutting Edge would have gone to the trouble of producing a separate mix of the track without this guitar. I'm sure it's not an alternate stereo mix from 1966 that's been unwittingly picked up from the vaults: the stereo would have been much wider back then.

This conflict seems impossible to reconcile at present.