I don't disagree.
I am just concerned that an unpublished documentation set has different information in it than the published documentation which is currently assumed to be correct. I.E. That however the API has been passed along from Dev to Dev, the internal documentation does not reflect that the external documentation dates from Helm's Deep.
This change is entirely invisible to Lua programmers. It replaces a value in the "Turbine.Language" enumeration with a stub value of the same name. The only documentation change I can think of would be to add a note such as "Russian is no longer an actual client language". Which it never was anyway, except in the Russian version of LOTRO, which had its own servers and an entirely separate client.
Again, please don't waste your time on this, Silorien.
I would guess (hope) that this change/comment reflects pending updates to the API.