Yes...and no. It really does "all depend". What it depends upon is the context you are using. So let's start with "what is Yin?"
To define yin or yang requires a context: in the context of location, in is yin and out is yang. In the context of heat, yin is cool and yang is hot. And so on (to see a complete description of yin vs yang check YinSights here:
http://www.yinyoga.com/ys1_0.1_yin_yang.php )
Restorative yoga is "yin" compared to many active forms of yoga, which would be yang if we are looking at the context of effort, heat, building endurance and strength, etc.
Where this can get confusing is when we refer to a particular style of yoga as Yin Yoga. (I generally capitalize the term to refer to the style of yoga as taught by Paul Grilley and Sarah Powers and through their students by many others.) Restorative yoga is yin because it is quiet, soft and healing compared to most other styles of yoga. But Yin Yoga is not restorative. (Again, see my definition of Yin Yoga in Yinsights here:
http://www.yinyoga.com/ys1_0.0_what_is_yin.php)
Yin Yoga (again, as opposed to a yoga that is yin-like) asks a lot of the tissues. If these tissues are damaged, we really want the area to heal before trying to exercise them, to increase strength and range of motion. When we are damaged, we want to do restorative yoga. Of course Yin Yoga can restore stability and mobility, so in that context most yoga can be considered healing, but I would not consider Yin Yoga to be restorative yoga.
To be more blunt: if you have an injury, don't do Yin Yoga for that injury unless you are working with a very experienced yoga teacher. Let it heal, then return to Yin Yoga to make it even better.
Let me know if you are still confused!
Cheers
Bernie
