Seems like you may have deleted the folders on the left before you ran the
Echo folder pair for the first time. If that's the case the behavior you're
seeing is exactly right. SyncToy doesn't know that those folders used to
exist on the left. With Echo you don't actually have a two way sync so stuff
which only exists on the right is never touched by SyncToy unless there's a
naming conflict of some sort.

Please let us know if you still have an issue with folder deletes flowing
from left to right after you ran the folder pair for the first time.

Ashish Shah
SyncToy Development