Okay, okay, okay ... How about this one:
Bannerlord is already finished, but TW is having too much fun to release it yet! Consider this quote from the most recent blog: "we all got into this business because we love to play games!"
Maybe while testing Bannerlord they got sucked up into their love of playing it that they are trapped, bound by infernal desires and greed to keep playing without releasing it to the wider world. It has become their precious, and in their greed they are unable to let go!
TALEWORLDS, IF YOU ARE READING THIS, IF YOU LOVE SOMETHING ... LET IT GO
OR
The game is so great, so powerful, and majestic, that releasing it would cause utter havoc and awaken the WORM OF WORLD'S END. WE MUST SAVE THE ELOHIM!