Apparently, this verse doesn’t count. In St Paul’s words,”So, then, brethren stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter.” (2 Thess. 2:15)
1 Timothy 3:15
15 if I am delayed, you may know how one ought to behave in the household of God, which is the church of the living God, the pillar and bulwark of the truth
Of course it counts! But seeing as "traditions" are teachings, where else do you find the teachings of the Apostles outside of the epistles and letters they wrote under the inspiration of the Holy Spirit along with the gospel accounts of Jesus' teachings along with Moses and the Prophets? Why would the Holy Spirit have neglected to include in Scripture all that pertains to godliness, for doctrine, for reproof, for instruction in righteousness so that the servant of God may be thoroughly equipped for every good work? This is the method God has used for thousands of years both before and after the start of Christianity to preserve His word. Jesus said,
"Heaven and earth will pass away, but my words will not pass away." (Matt. 25:35)
The grass withers and the flowers fade, but the word of our God stands forever. (Isaiah 40:8)