I think the Teradata guys first adopted that expression - basically to try and establish data retrieval benchmarks on their huge data sets.
As to your question sure - but stabliity issues and performance issues should be covered by an effective/complete monitoring process that will involve more than just canary queries.
http://www.tdwi.org/research/display.aspx?ID=6360
I.e. queries can determine generic response times and also test if the communication to the CMS is both active and fast, but you also have the OS, memory, CPU and web/application(s) to consider.
The SAP vendor has a few papers out re monitoring via Tivoli and MOMS that you should get your hands on - also search BOBJ:
MikeD 
(BOB member since 2002-06-18)