Any person who eats any blood, even that person shall be CUT OFF FROM HIS PEOPLE

[TonyChanYT]

Leviticus 7:

27 Any person who eats any blood, even that person shall be cut off from his people.

What did "cut off from his people" mean?

Leviticus 17 offered some insight:

10 any man from the house of Israel, or from the aliens who sojourn among them, who eats any blood, I will set My face against that person who eats blood and will cut him off from among his people.

Would this simply mean they were cast out of the camp and never welcomed back?

Wiki:

The Hebrew term kareth ("cutting off" Hebrew: כָּרֵת‎, [kaˈret]) is a form of punishment for sin ... In the Talmud, kareth means not necessarily physical "cutting off" of life, but extinction of the soul and denial of a share in the world to come. ...
In the Hebrew Bible, kareth is a form of punishment which may mean premature death, or else exclusion from the people.[3][4] According to Richard C. Steiner, the phrase "to be cut off from one's people" is an antonym for "to be gathered to one's people" (e.g. Genesis 25:8), and thus kareth in the Bible means to be deprived of the afterlife.[5]
Examples of sins making a person liable to kareth include eating chametz on Passover,[6] sexual violations,[7] ritual impurities, and a man's refusal to be circumcised.[8] The Book of Numbers states that anyone who sins deliberately or high-handedly receives kareth.

Rabbinic interpretation:

Kareth is the punishment for certain crimes and offences defined under Jewish law (e.g. eating the life blood of a living animal, eating suet, refusing to be circumcised, etc.), a punishment that can only be given at the hand of heaven unto persons of the Jewish faith who are bound to keep the Jewish law, rather than made punishable by any earthly court. In some cases of sexual misconduct and in breaking the laws of the Sabbath, such as where there are witnesses of the act, the court is able to inflict punishment. By definition, kareth does not apply to non-Jews. Kareth can either mean dying young (before the age of 50 or 60[10]), dying without children, or the soul being spiritually "cut off" from your people after death.[11] According to Nachmanides, both definitions are accurate

What did "cut off from his people" mean?

He would no longer be a citizen of God's kingdom of Israel.