"Abusing" is not synonymous with "violating."

If we sign a contract that says you're allowed to park in my driveway in exchange for $10, then I threaten to sue you for parking in my driveway, technically I'm not violating our contract. It's not an issue until I actually sue. But I'm still abusing our contract by threatening you for doing something I explicitly allowed you to do.

Likewise, Bambu was able to benefit by forking and distributing AGPL software in exchange for giving everyone a license to do the same for their fork. Then they turned around and threatened legal action against someone for doing what they previously said was allowed. This may not technically be a violation but it's definitely abuse.