My gut feeling here is that these feast were indeed mandated and upheld until the Temple was destroyed.
I don't have any evidence other than the following verses and the DSS.
Now the "tithes" mentioned I believe would be from the Pentecost Feasts because of the amount the Priests would need to sustain them and use in the offerings as well over the year. I can't find any detail in the OT as to how much FirstFruit of wine was to be offered. The DSS does give some amounts.
And thou shalt eat before the LORD thy God, in the place which he shall choose to place his name there, the tithe of thy corn, of thy wine, and of thine oil, and the firstlings of thy herds and of thy flocks; that thou mayest learn to fear the LORD thy God always.
All the best of the oil, and all the best of the wine, and of the wheat, the firstfruits of them which they shall offer unto the LORD, them have I given thee.
2 Chron 31:5
And as soon as the commandment came abroad, the children of Israel brought in abundance the firstfruits of corn, wine, and oil, and honey, and of all the increase of the field; and the tithe of all [things] brought they in abundantly.
And [that] we should bring the firstfruits of our dough , and our offerings , and the fruit of all manner of trees , of wine and of oil , unto the priests , to the chambers of the house of our God ; and the tithes of our ground unto the Levites , that the same Levites might have the tithes in all the cities of our tillage.
For the children of Israel and the children of Levi shall bring the offering of the corn, of the new wine , and the oil , unto the chambers , where [are] the vessels of the sanctuary , and the priests that minister , and the porters , and the singers : and we will not forsake the house of our God.
And he had prepared for him a great chamber, where aforetime they laid the meat offerings, the frankincense, and the vessels, and the tithes of the corn, the new wine, and the oil, which was commanded [to be given] to the Levites, and the singers, and the porters; and the offerings of the priests.
Too, I'm thinking there is nothing in the Mishnah on this because it was atonement for the wine when in the land and also, the Pentecost of New Wine was a milestone of the New Covenant and from what I gather great efforts were made to destroy any remnants of this movement over time.