Indeed, if an alias is changed or deleted, any rule based on that alias will stop working without any warning from the system. The values will remain in place until the cube or its rules gets reloaded but you will only get a "silent" warning in the messages log after reloading the cube.
Renaming elements without activating aliases? Yes we can!
The dimension editor and dimension worksheets cannot rename elements directly, so let me introduce you to SwapAliasWithPrincipalName.
In this example, we will add a padding "0" to an existing set of elements without rebuilding the dimension from scratch.