As you suspected / hoped, this is just a bit of item level shifting across the board, with this particular change going in earlier than others. In the end, the epic crafted gear item level will not be changing relative to other gear.
Currently the intention is quality 4 mythic upgraded profession gear will be equivalent to the early bosses in mythic raids, with quality 5 being 3 item levels above that.
You should see these new item levels reflected in the next patch on Beta.
I will note that because this is Beta, we will be continuing to evaluate the specific role crafted gear takes in the overall gearing ecosystem, but our intention is absolutely to keep crafted gear as an important contributor to your gearing journey.
Sorry for the confusion.