SQL Server : reasons not to use default database settings for ANSI_NULLS?
It is not a risk at all.  In fact, the ability to turn ANSI_NULLS OFF has a limited lifespan. Soon enough that won't even be an option, it'll always be ON. The only time I've ever seen any form of reasoning for setting ANSI_NULLS OFF, is because there are developers that can't fathom the true meaning of NULL, and therefore want to use typical conditional logic with it. Again, terrible reasoning and not justifiable.  I look forward to the permanent ON setting for ANSI_NULLS.