We currently do not backup Gerrit's indices. As of 2020-07-12 they need ~4GB of disk space.
In case of disaster, the indices can get re-generated from the repo data. Only, it takes some. So recovery is longer, if we do not back it up.
If we want to backup indices, we should do so.
If we do not want to backup them, it would help to make intent clearer, if there was a remark in puppet declaring it as "not backed up on purpose".
(Just to avoid doubt, we can recover from desaster without indices just fine. Only, it would take longer.)
(This is unrelated to the recent Gerrit 3.2.2 upgrade. Indices were used before our old Gerrit 2.15 just the same, and we did not back them up there either.)