You imply there is a difference between the two. Not everything is necessarily propaganda.
Without delving too much into real world religion and politics, I'll simply note that a great number of gods, saints and holy men throughout the years can be quote mined to support almost any stance or issue you may wish to promote, even if it's contradicted three pages later. No need to quote that verse. Quote only what supports your agenda. Exclude the rest. Not a REAL lie, but a backhand lie. A lie through exclusion.
I can easily see the Tribunal being corrupt in this way. Glorifying the aspects of Veloth's teachings that fit the Tribunal canon and glossing over or excluding the rest. Hence the whole Anticipations thing - it was really quite genius what the Tribunal did. Veloth's teachings extolled the virtues and gifts of the three Good Daedra, so what better way to pretend to continue in the Velothi tradition than to supplant and wear the identities of the patron gods?