If you're in fox sports KC viewing area, you definitely do get the channel if you choose that option through SlingTV.
I've had SlingTv since early May. I'd give it a solid C+ grade. It's not great...the interface could use some major upgrades...and every once in awhile I have buffering issues, but it's been pretty decent. Picture quality is good.
So yeah, if you're hellbent on getting rid of cable this week, and still being able to watch the final few Royals games of the season, get the free 7 day pass and try it out.
I guess I'll keep it for awhile to see how much I use it during college football season. I tried a free trial week on Playstation Vue and thought it was a better product, but it doesn't have FSKC yet.
And, of course, if you're looking at cutting cable, be sure you know about stuff like Kodi and Firesticks etc...