hello, Michael provide you good advice, i will add few more :
Public IA and local company IA work very differently.
Public IA use all the public knowledge of the world to answer.
Company IA are trained differently to use dedicated content.
Giving a lot of document with outdated content is not recommanded. IA best practise is to have a dedicated knowledge source with the content only need by the IA. It will help to ensure the best quality answer over time and control on that quality. Easy way is to use publishing mecanisme to send content to dedicated folder or made them moderated by a an expert.
Making some workaround to hide some content will one day or another tend to bad quality result.
But we know real life is complicated and some time different, or very complicated to have best case
Microsoft recently added to sharepoint connector date filter so you can exclude content after a certain period :
to conclude, since you have this workaround, remind that all company great IA solution all use "hidden" database or dedicated folder with only the datas they want, so it's a good practice to clean :)
I hope this help, if yes please verified the answer it's important for the community and search engine :)
