It's not baseless, it's logical. There is a huge incentive for Delta to state "customers can rest assured they were never installed on planes". There is no possibility that they don't know since they're required by law to document use and location of all parts and tools they use for maintenance.
The OP's assertion lacks foundation, and hence can correctly be classified as "baseless". If the OP has proof then they should come forward with it; if the OP lacks proof then ipso facto it is "baseless".
You are confusing "no base" with "no evidence". A basis can also be logical support. And OP has outlined the logical (decision theoretical) foundations of their reasoning pretty clearly.
