It just smacks of Scripture twisting.
There were no obligatory, annual festivals/feast days formulated anywhere in the Bible apart from Moses and the children of Israel as they ventured from Egypt to Sinai. They were all part of the temporary shadows given to the children of Israel to point to the coming Messiah. They were all bloody. They have all passed away since the once-for-all-time sacrifice of the lamb of God.
This suggestion doesn't even pass the smell test. Where in the Bible does a one time, unique command establish an abolishing of God's Feast Day observances? Hint: Nowhere!
There being a multitude of scriptures instructing God's people to observe His Feast Days "Throughout their generations.....forever", it is absolute silliness to try and explain them away as discontinued.
The Holy Days did not originate with the Book of Leviticus, nor the Levites. The Levitical system did not begin to operate until the children of Israel had been wandering the wilderness for a year [Exodus 40:17-19]. So.....conversely, when the Levitical system was abolished [Hebrews 7:11-14] it had nothing to do with the Feast Days which were put in place (Biblically prior) to them. And.....as I have stated, most likely established during the time of the Patriarchs, prior to the captivity itself.
This is about as silly as folks attempting to say the observance of the Sabbath has been discontinued when they know full well that The Lord instituted it in Eden [Genesis 2:2-3], ordained it as a permanent observance [Exodus 31:12-17].... and never un-ordained it!
The Lord Jesus didn't just command his followers one time in scripture to observe his feast days. He does it multiple times. Check Exodus 16, Exodus 20, Exodus 12, Exodus 34, Leviticus 23 and Deuteronomy 16. In each one of these chapters he instructs his followers to observe His holy days.
Concerning new covenant observance, Paul SPECIFICALLY instructs gentiles followers to observe the feasts of Jesus Christ the Lord:
1Co 5:7 Therefore purge out the old leaven, that you may be a new lump, since you truly are unleavened. For indeed Christ, our Passover, was sacrificed for us.
1Co 5:8 Therefore let us keep the feast, not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth.
Paul understood that the feast could be kept without sacrifices. It's Paul himself who set the example of feast keeping for new covenant followers of the Lord.