The 18th single is actually foreshadowing the results of the 19th senbatsu:
Title
BEGINNER. Does that name ring a bell at all? It should, because that's what a majority of the 19th senbatsu are. Uchida Mayumi beginning a new journey as a center, thrust into the media spotlight with no experience whatsoever. Does that sound like anyone else? Of course, BEGINNER's center, Maeda Atsuko.
Limbs getting cut off
The beginning of the end. Quite literally, a body without limbs is one that is destined to die. AKB48's frontgirls getting cut from the main body (the senbatsu) is the path to destruction for AKB48.
The fusion of fantasy and reality
The girls play a PSP-like console, where the reality is inherently connected to the fantastical universe they're in. Isn't that exactly what happens in the 19th single? Fan's dreams of lesser-known girls are finally getting a chance at senbatsu. Fantastical method, real-world consequence.
The competitive setting
Competitive setting, Jankenpon tournament, anyone?
Watanabe Mayu getting stabbed
Not just stabbed, but from all directions. What does this mean. As you may know, Yama-chan was the chief ref for the event. And yet, Mayuyu lost. What does this mean? An "Et tu, Yama-chan?" moment, of course. Mayuyu now has no one she can trust. Even the one she depended decided to bail on her. To her, this was more than just a stab in the heart. It was a million stabs to the body.
Maeda Atsuko screaming
This is actually a million signs in one. Maeda Atsuko foreshadowing the dawn of the new AKB48, where she is replaced by Uchida Mayumi, and the fact that she couldn't stand all the competition. She had to kill off Mayuyu to land a spot in senbatsu.
Conclusion
19th single is fixed.