Ephesians 6:21-22 and Colossians 4:7-8: Tychicus gave personal updates, not letter interpretation

Ephesians 6:21-22 says Tychicus 'will tell you everything' so they'll know how Paul is doing -- this is personal news about Paul, not interpretation of the letter. Colossians 4:7-8 is the same: Tychicus will tell them about Paul's activities and encourage them. Neither passage supports the idea that letter carriers taught or interpreted the letters they carried.