I have a tauren paladin, she was level 63 or 64 prior during the Legion expansion. She was in Outland and had her baby flying mount.
I left WoW shortly before the BFA pre-launch event and returned for the Shadowlands pre-launch event. Post level squish, my paladin was level 27.
I decided to finish leveling her to 50. I asked Chromie to assign me to the Cataclysm timeline. I was told to check the Warchief's Command board, but it only offers me the zones Western Plaguelands, Badlands, and Townlong Steppes (Pandaria). After clicking the board, I get a "Talk to Chromie in the Valley of Honor" follow-up. She's right near the board I clicked in the Valley of Strength. I talk to her and the quest completes, and she disappears, and that's it. If I talk to her again at her main spot near the Ogrimmar Embassy, she asks if I want to choose a different timeline or return to the present.
I went into Grommash Hold, and General Nazgrim offered me a quest to "Present myself to the warchief." I accepted, and the cutscene that begins Pandaria for the Horde played. Nazgrim offered the follow-up quest, "All Aboard," to begin Pandaria, and I didn't accept it.
I can't get the quest to begin Vashj'ir. It's not offered on the Warchief's Command Board, nor by Farseer Krogar on the high cliff in rear Orgrimmar, where the portals to the various Cataclysm zones are.
Am I doing something wrong? Is there any reason why the breadcrumb quest to start Vashj'ir isn't being offered?
EDIT: Despite the quest saying to talk to Chromie in the Valley of Honor, she is not there. When you click on the Warchief's Command Board in the Valley of Strength, she appears right next to that board in the Valley of Strength.