I agree that these restrictions are an older group; that is probably why the Council of Jerusalem did not lift those. They are called Noahide Laws, as opposed to Mosaic laws. But Christianity is generally not about formal laws. We are very much against fornication and idolatry not because God said so to Noah but because the law to love God commanded that even before anything was told to Noah. As to blood and the method fio slaughtering livestock, there is not natural law against it, so the Church gradually dropped those.
We are saved by grace alone and not by the works of the law.
“the Church” cannot revoke the principles God has set, hence calling it “Noahide Law” and making a leap from that to,
“We are saved by grace alone and not by the works of the law.” is unwarranted and misses the whole purpose of God’s pronouncement on the restriction on blood use.
Those “necessary things” are still necessary in obedience to the Scriptural principles.
“the Church” could no more drop restrictions on blood than fornication.
But Catholicism is. Lots of them.
Which is why people are leaving the Catholic church in droves.