Well there is another verse from the new testament that also prohibits blood
Acts 15:19 For which cause I judge that they, who from among the Gentiles are converted to God, are not to be disquieted.
20 But that we write unto them, that they refrain themselves from the pollutions of idols, and from fornication, and from things strangled, and from blood.
21 For Moses of old time hath in every city them that preach him in the synagogues, where he is read every sabbath.
But was it as verse 21 says maybe for people not to get confused?
As Jesus before that had declared all food permissible and clean, and surely the apostles must have known this.
So was it a prohibition for avoiding confusion amongst the jews?
Or did the gentiles also have some prohibition of blood?