This may be an oversimplification, since many of our customs as Christians (including head coverings, which Paul endorses, or fulfillments of Jewish feasts such as the Tamid, Passover, etc) have their roots in Judaism. There is no reason to assume that disciplines such as celibacy vows ceased with the advent of Christ. For an example of this, Levitical priests offering sacrifice for their month had to remain celibate. This same concept is found in our priests today, who are perpetually celibate due to their daily offering of sacrifice. The original basis for such disciplines has not changed, and so are not disposed of. Your interpretation of a seemingly rather clear statement by Paul seems to rest on the assumption that Paul could not have meant that because no such vows existed. Perhaps you could provide a reference for your statement?