But, it's like, "where's the hard fucking evidence?" Stop hiding stuff!
It's not just the aliens trolling us. It's the gov/corp too.
Maybe that's all part of the aliens plan: they know that by their tech-striptease they will drive the gov/corp wild with the promise of tumescent technology and send them into a no-holds-barred frenzy to squirrel-hoard all the nuts for a future time when they might just understand it.
In doing so, turning the gov/corp and the people further against each other (not like history is clean of examples of pre-existing exploitation), further weakening humanity (by crucially weakening its lynchpin: the public, the state).
From that view, it's sort of like a "kindergarten teacher" play: the teacher spots a troublesome youngster bopping others on the head with a toy. So the teacher gives the youngster a shinier toy, then youngster proceeds to sit in the corner and play with said shiny until it falls harmlessly asleep.