When placing a piston, you can see it redirects the redstone, however. This is only visual as if you put a lamp on a row of redirected redstone into pistons for example, it will still activate.

Steps to reproduce:

Make a line of redstone, place pistons on the side of the line.

Place 2 blocks on the end of the line

Place 2 redstone torches ontop of the blocks

Expected result:

The pistons redirect the redstone and the torches wont turn off.

Observed result:

The pistons only visually redirect the redstone and the torches turn off.