I've noticed that on my machines that have Windows 10 Pro (Desktop, SP3) don't have it as an option but two laptops with Windows 10 Home do have it. I'm not sure how/if you can activate it but maybe they think those using the Pro version don't need it... :/
It seems spotlight was removed from the Pro version, we need to upvote the feedback to re-enable it in the pro version as well! Pro version should means more features, not less!