As part of the overall shift to use py3 as the default, instead of py2, the "canonical" lsstsw based build env used for publishing eupspkg should also be switched to py3. This inherently requires removing local state to prevent py2 / py3 linkage problems with previously installed eups products. Removing the installed eups products would cause the eups <version>+<build> sequences to reset. This can be mitigated by doing an eups distrib install of the most recent nightly release when starting from a clean workspace.
Additionally, there has long been a desire to migrate the "canonical" build off of lsst-dev, primarily motivated by performance issues with the filesystem ~lsstsw resides on. As this would also inherently involve a loss of state, it is nature to combine these tasks.