In large projects you have multiple versions of an application installed in multiple places. It is not like you have one location and it has either old or current version - you have few branches and one already has current version and the other one does not (due to various organisational reasons).

Redmine could track update/version deployments in location/branches.

The change IMHO is not big - you just need to add a module that allows to register various location/branches and then relate it to issues.

It can be done with custom fields but this would be a workaround.

Again - basic idea is that it is mandatory that in big systems rollouts do not occur in the same time.