No, it isn't a come back to communist times. The Croatian government has decided to ban Christmas and New Year parties in the public sector because of the global financial crisis. It is just a way of saving money, assuming that the Croatian economy does not produce goods associated with corporate X-mas presents. The BBC doesn't say if holiday decorations are banned in the offices too. At least Croatia enjoys mild Mediterranean winters, so people won't have to endure a dark and gloomy December like in northern Europe.
BBC News : Crisis squeezes Croat Christmas