I think that's just a result of the term falling out of common use in the US. I'd expect 30 years ago "Spooks" would be a perfectly fine name for a TV show in the US. (I remember watching spy shows/movies and reading spy novels as a kid in the 80s/90s and hearing/reading that term.)

It generally doesn't. People should stop reviving the negative connotation. Sure if someone is calling a black person a spook let's call them out but if that's not how it's being used let's not insist it's an inherently racist term. It's totally counter-productive.

Not what you are doing, just elaborating because while it can be used as a racial slur it doesn't generally have that connotation. I think if you directly asked most people they would either not know about the slur or not be able to specifically identify the targeted group. We can choose to let the term die.