I don’t think the Revan event will be a Hero’s Journey. Why? (Beware slight Kotor spoilers).

I wouldn't discount a raid option. Could just be a mythic version of the rancor with some increased difficulty. That may or may not put it more difficult than hstr. That likely depends on how op his kit is.

If jedi revan is a raid reward but only good but not amazing (as a setup for a later hero's fall or journey) the raid difficulty could be more than haat but less than hstr. But if he's meta changing, then likely the raid would be hard.