We have some cases were a certain solution was replaced by a newer solution (with different structure, different hosts, different log retrieval and different log info etc...). Therefore we now have two indexes, one old and one new, one active, the other as archive.
Since spunk doesn't have index alias, we thought if it's possible to add some kind of alert each time a user searches by the old index. A small message is enough, for instance something like 'this index was disabled on 01/01/2015 and replaced by index X', just like the one you get it you change your time range explicitly on your search.
P.S. - instead of the messages, a possible solution for this problem might be making the user search using a macro with the name of the system and the macro would expand to index=old Or index=new.