Not necessarily.
This article is a quick read about how shadows can be FTL as they're not actually a thing, just an area where photons aren't. Now, most shadows are not actually faster than light, and saying that shadows are faster than light is a little bit disingenuous.
Also, in fiction shadow's do work differently (say for example shadow manipulation isn't ftl unless the character is ftl), so it would be best if we had context.