<quote name="Platonides" date="2013-03-25" time="23:03:22 +0100">
Not exactly a guarantee, but the general rule we use is to keep deprecated for a couple releases before removing. It's briefly explained at http://www.mediawiki.org/wiki/Deprecation
Thanks for the link, but the reason I brought it up is because my first week here I saw a removal of a function without an explicit @deprecated warning.
:-)
Greg