Generally, yes.
To be absolutely 100% sure you would need to use all custom objects and then you have full control over the archive / unarchive process. But, so long as all the classes are appropriately using the encode and decode methods of the keyed archiver then everything will be future compatible.
If Apple ever did decide to break this for some reason, you best option is to catch the resulting exception and inform the user that they will need to obtain an upgrade to the app.
Your alternate approach is to store the initial deployment of data in a different format (like JSON, maybe compressed) then at app startup if you have an existing version, use it, if not, read in the initial deployment data.