Event Flags for Rock Climb

So, qualifying statements here… In my playthrough of the game I have: collected 8 Badges, completed the first set of events at the Throne of the Hegemon, and also collected the Work Up TM from the Blackbelt in Minda town way back when I first passed through it.

On my way through Crystal Caves I encountered a Druggion and thinking about an in-game trade I hadn’t yet made for any dragon type thought, “as good as any.” During the battle, I discovered that it knew Rock Climb. Catch. Quick party swap so Druggion is now in party, and go to nearest rock climb location I can remember. (Area 3, Crystal Caves.) Interact with Rock Climb area. “These rocks seem climbable.”

There is no prompt to climb them with Rock Climb.

Go into Pokémon screen and interact with Druggion. Can see Rock Climb as a field move. Press it. Minimenu disappears, but nothing else happens.

Also I’ve read on the Wiki that the Black Belt reappears in Narra Poke Center to give Rock Climb. I have not yet seen him. So I’m simply assuming that there are event flags that I haven’t tripped to be able to use Rock Climb as a field move. (I’m guessing it’s post-game exclusive?)

Is this correct, or am I missing something obvious instead?

Rock Climb is post-game exclusive, you get it in the Perfection Base post-first E4 run.

it comes in the form of hiking or climbing boots one of the 2

Hiking Boots

You’d need the Hiking Boots Key Item in order to climb rocks in Insurgence, this is to ensure that everyone gets Rock Climb at the same time and that no one has an unfair advantage earlier by catching a mon that has Rock Climb.

Rock Climb is obtained in the beginning of Taen’s postgame quest, for which the Postgame Guide can be found here. This quest is post-E4 victory as well as after defeating the Timeless. Be aware of spoilers on the page, though.