To avoid the complexity of maintaining seldom used and seldom tested code, we should remove the upgrade script for moving from pulp 1.x to 2.x from our codebase. As long as we keep the 2.2.x series in our repos, it should be a safe plan to require users to upgrade from 1.x to 2.2.x, run the upgrade script, and then upgrade from there to whatever the latest version of Pulp is.
There is now a story for this scheduled for the August sprint.