Create v0.2.2b added the ability to move Mechanical Pistons/Bearings and Pulley, and when directly in front of a piston this works as expected. However, if attached to a sticky linear chassis instead, not all of these blocks can be moved.

Here's a video showing this behavior in a nutshell.

Also, vanilla pistons are not able to be moved at all, is this intentional?

Related and reported on the Discord, Mechanical Pistons can also be rigged to push themselves, easily observed by putting a slime block in front of one. Can even cause dupe glitches!

This issue has been addressed in 0.2.3. Thanks for the report and feel free to re-open if need be.