Having not realised quite what you were referring to and now after a quick Google search I am left slightly mystified. I am sure it is common knowledge (just not to me) that in 2011 Moscow time was changed to be permanently GMT +4 and the 5130 and 5131 time zones were changed to reflect this (not sure when the change occurred) and then a further change was made in July 2014 to permanently move Moscow time to GMT +3 which now means the current time zone indication on 5130 and 5131 is incorrect.
The odd thing to me is that a new model introduced in 2015 (5131R) continued with the old out of date time zones when it had been changed a full 7 months earlier to GMT +3. Presumably to keep all the 5130 and 5131 range the same although I doubt that will continue when/if the revised World Times are announced.
Perhaps the 5131R will change as well? I guess all will be revealed soon.