The problem with ascetic traditions or traditions that highly exalt solitary contemplation as a way of life is that it is inherently Unitarian. On the other hand, Trinitarian theology calls for celebration and feasting in community as a way of life, since the Trinitarian God has always enjoyed perfect unity and fellowship with one another from all eternity past.
So long as the groom tarries, the wedding party fasts. Aesceticism can be traced to earliest Christianity. Properly understood, it is deeply rooted in incarnational theology and it is strongly eschatological. It may be more readily understood in relation to a robust doctrine of theosis.
To fast would be to assume death; but Pascha has come! Sadness is gone, feasting has come. The wedding party feasts continually, and then it will feast again when the groom comes…this is rooted in the resurrection, a notion many in the early church missed.
Unless you want to consign Mark 2:20 and parallel passages to the days between the crucifixion and resurrection, fasting is pretty much a given. Acts 13:2-3 and 14:23 show the apostles engaging in fasts, and I think a case can be made for correlating 1 Corinthians 9:25-27. The word Paul uses there gives us the word “agonize.” The Didache provides instructions on it. There are epistles condemning licentiousness and also extreme asceticism (the kind that leads to a denial of the goodness of creation, marriage, etc.). However, the command to fast has not been rescinded.
You are right. Fasting has not been rescinded. However, my point is that it is not the highlight nor center of Christian living in the New Creation (post AD 70). In other words, eschatology is present, or you can say, the future comes to the present or you can say resurrection is now and evermore, world without end.