LibrePGP is also a rewrite. To keep supporting legacy v4 you have to keep having v4 code no matter if the new thing you add is v5 (LibrePGP) or V6 (the RFC)
actually neither are complete rewrites. i played around with diff and found that the new version of OpenPGP seems to keep about 60% of the old one and LibrePGP seems to keep 90%.
so the rewrite claim was exaggerated. i didn't compare the stuff that was added or merged.
The claim is even more exaggerated than that, because a lot of the diffs between 4880 and 9580 are editorial and structural, and don't have any semantic effect.
so the rewrite claim was exaggerated. i didn't compare the stuff that was added or merged.