If you are talking about abstracting, i.e. taking away, similar bits of code into one place in programming, whether it's via polymorphism or refactoring functions, then no, that is not a "leaky abstraction".
I am talking about abstraction as in creating a simplified / unified interface over some complex thing. Abstracting the idea of something from its concrete realizations into its own concept. OSI networking layers, drivers for hardware, modeling real world systems, etc.
If you want to be pedantic instead of snappy, you can change my statement to "all abstraction layers are leaky".
