The Matthew portion describes the Passover meal and the John portion describes Jesus washing His disciples feet. Do you suggest that we should all literally wash one another's feet or do you believe there is a symbolic or spiritual meaning in what our Lord did? If the latter then everything He did was of the same order. That is the point.
Ritual and collective observances are the very stuff of religion and have been from the beginning of time. Every religion is made up of such activities that are endowed with some significance for the faithful but are of little spiritual worth. If the Lord Jesus Christ taught us anything it was that such observances are futile.
The Lord Jesus Christ came to inaugurate the Kingdom of God in its spiritual reality and to fulfil and put an end to the prophetic shadow elements of the Judean Church of Passover, the remnant of the ancient nation of Israel. Any return to that shadow realm is a retreat into darkness and away from the Light of the Spirit and Truth that our Lord commanded us to be.
"Jesus answered them: 'Truly, truly, I say to you, everyone who commits sin is a slave to sin. The slave does not remain in the house forever; the son remains forever. So if the Son sets you free, you will be free indeed.'" (John 8:34-36)