It depends on what the actual release versions are.
Simulink is backwards compatable, so a model from an earlier release should be able to run in a newer release. If you create your model in a newer release only using what existed in the earlier release, then it should also be able to run in both versions.
However, if your model uses functionality that did not exist in an earler releaes, then you will get an error when trying to run it in the earlier release.
