A rumor surrounding Danny Boyle’s departure as director indicated that it involved the casting of an actor named Tomasz Kot as a Russian bad guy.
The rumor claimed Boyle was clashing with star Daniel Craig over the choice.
Depending on the validity of this rumor, it could be that the bad guy has actually already been cast and the producers decided to go with the Russian bad guy instead of the Middle Eastern one.
It seems that while the final decision on who the next Bond villain might be has yet to be decided, Said Taghmaoui is one of the last people in the running.