Is a knife still considered full tang if the handle portion is skeletonized?

[eisman]

Pins or screws that pass through the tang are clearly visible on the handle.

Not always. I know several makers who use blind pins.

 

[microbe]

Not always. I know several makers who use blind pins.

Informing the customer about hidden features is key. Those makers obviously told you they use blind pins, or you would not even known about it. Good guys.
I bet they tell their customers about skeletonizing to, instead of calling it plain full tang.