What I got with Recovery Disk Assistant?
Yes, it is a Yosemite recovery USB flash drive. The application copies the hidden (internal disk) recovery partition to the flash drive. I believe Apple no longer recommends using a recovery flash drive, so I suppose they have not updated the Recovery Disk Assistant application. I believe Apple now wants you to keep a bootable copy of OS X on an external drive. Still, the recovery flash drive is good to have if you need to download and install a fresh copy of OS X (and your internal recovery partition is damaged). Some will argue you can just boot using internet recovery to reinstall OS X, but you will get the version of OS X that was shipped with the machine. If you keep your flash drive up to date, then you can download the current version of OS X (that you have installed).