The joke KFC landed on, which you can see above, is rearranging the letters of its name. Yes, that doesn't sound as funny when you explain it, but you're not supposed to explain jokes anyway, remember?
For context here, England experienced a KFC "chicken drought" because the fried chicken chain switched food distributors in an attempt to save money. The delivery partner, however, wasn't able to follow through on its commitment. Around 700 out of the 900 UK KFCs closed at the beginning of the week because there wasn't any to C to KF. And that was not OK.
This was the first (less successful) attempt to lighten the mood: