Is it reasonable to assume that the code could be updated and still work? The answer to this question depends on many factors.
If we're talking about MS SQL Server, stored procedure, functions, views, etc., all reside on the server or operate on the server. When we're talking about databases, they're not typically updated until it is 100% absolutely necessary.
SQL Server 2005 is getting a bit old today and there have been several versions of SQL Server since this version... yet there are tons of SQL Server 2005 servers in use today. Language features added since SQL Server 2005 simply won't work on a SQL Server 2005 server. In a case such as this, the server version should be specified in the question, and answers using language features that won't work on the specified server version should be downvoted at a minimum.
On the other side of this coin however, I'll provide the example of Objective-C and iOS development.
When a new version of iOS comes out, users quickly upgrade to the new version and at a high pace.
As of this posting, over 87% of all iOS devices are running iOS 7.x, and another 10% of users are on version 6.x, leaving fewer than 3% of all iOS users on version 5.x and lower. Another interesting aspect is when you look at the per device breakdown and see that the bulk of iOS 6.x users are on either the iPhone 3GS or the iPod Touch 4G, neither of which is capable of upgrading to iOS 7.x.
iOS apps are always doing one of two things. Either they're constantly updating themselves with new language features introduced by the new version of iOS, or they're not being updated at all. Extraordinarily rare is the iOS developer who is still updating his app, but needs to continue to support devices on iOS 5.x.
As such, an answer posted to an old Objective-C question which suggests new language features is absurdly appropriate because either the asker simply won't care to look at the answer because he's no longer maintaining that code (in which case the answer doesn't hurt), or he IS updating his app still and he is always pushing for it to be as modern as possible.
And in fact, while SQL Server questions should specify what server version they're on, I'd recommend iOS questioners let it be known if they're waiting for iOS 8 (or whatever next version) before their release so that EVEN NEWER features of the language can be suggested!