No, the existence of bitcoin is not a threat to jobs and national currencies as it is also like a currency but it is digital and used as payment option like fiat in many countries and no threat to those countries job. It is in the growth stage and a lot of revolutions comes in it in the future as more and more countries moving towards this technology and it will create new jobs not a threat to old ones.
In my opinion, bitcoin is not a threat to the national currency because they have different uses and bitcoins can not be used for valid payment instruments. Maybe bitcoin can be used for legitimate payments in the future but the existence of national currency of each country also will not be displaced by it because bitcoin is the virtual currency