Because those versions aren't part of the history of the 1:0.8.4-4
package. You're rolling back and branching earlier, so changes from
the discarded branch are irrelevant.
but Filip is not rolling back whole package, but only upstream version. Other changes in packages are kept in place (for example TZ patch).
So, should he mention those changes in 1:0.8.4-4 changelog entry (merge them)? We will then "lie" in unstable that this changes was done in 1:0.8.4-4 but they was done in earlier versions.
TBH, IMHO best solution is TPU for that TZ+copyright patches and don't rollback anything in unstable :)