With the experimental dust changes, dust going along a left/right split is intended to choose its direction randomly, but in the attached video, you can see that when you have multiple splits in the dust, the result will always be internally consistent (if the dust preferred left on the first split, it will do so again on the second split), and vice versa.

Steps to reproduce:

1. Import and enter the attached world: MC-275317.zip
2. Activate the pistons multiple times

Observed result:
Both pairs of pistons always activate the same way.

Expected result:
Both pairs of pistons always activate randomly.