Language is changing constantly as we can see in the case of the accusative or object form "whom" (question word and relative pronoun).
In colloquial language "whom" has vanished. The m has simply been dropped.
In written formal language "whom" is still used.
It is not a matter of deprecation, but one of up-coming new usage (at first always in spoken language) andwith the older original form (keptbeing kept in formal written language for a long time).