I race changed my orc monk Oshgaru to a Zandalari monk (this character), and I no longer seem to have trust level 3. My post history has also disappeared.
Is it intentional that we lose our post history/trust level in the event of a race change, or should I file a support ticket?
Although not ideal, currently, it is intentional.
There are some side effects due to the unique nature of Wow’s forums having to deal with multiple profiles per player. The web teams are working to improve how that and many other things work.
Although there’s no way to get your TL back currently, you can use this link to follow your old post history. Just insert your old char’s name exactly as it was (assuming Wyrmrest Accord):
https://us.forums.blizzard.com/en/wow/u/xxxxxxx-wyrmrest-accord/activity
You can bookmark it for easy retrieval.