Obviously, Matthew 15:11 is true; what goes inside of you does not make you filthy before God.
However, it does seem that abstaining from blood hasn’t actually changed in the NT.
See Acts 15:24-29 NKJV
24 Since we have heard that some who went out from us have troubled you with words, unsettling your souls, saying, “You must be circumcised and keep the law”—to whom we gave no such commandment—
25 it seemed good to us, being assembled with one accord, to send chosen men to you with our beloved Barnabas and Paul,
26 men who have risked their lives for the name of our Lord Jesus Christ.
27 We have therefore sent Judas and Silas, who will also report the same things by word of mouth.
28 For it seemed good to the Holy Spirit, and to us, to lay upon you no greater burden than these necessary things:
29 that you abstain from things offered to idols, from blood, from things strangled, and from sexual immorality. If you keep yourselves from these, you will do well. Farewell.
A lot more could be said, but this is a simpler answer.
This is not the most popular idea where I am located in the US, either.