I’m headed to the World in 6 days. I’ve been watching the hours and MK is the only park to extend hours. CL is much higher around Columbus Day (fall break) yet HS and AK are still closing at 8… and they both have evening stuff scheduled after 8. (ROL at 815, STAR WARS fireworks at 8:30…)
Is there a chance they’ll extend these hours for AK and HS?? I can’t imagine why they’re closing so early. They closed later on some CL 1 and 2 days in September. 
There’s always a chance. They have extended hours as late as day of. But those times for the evening shows really have nothing to do with extension of hours. It is not uncommon for those 2 shows at those 2 parks to start after park closing.
There’s always a chance, however, at 6 (now 5) days out, I’d consider it incredibly unlikely.
Basically, what the times they’re showing are telling you is that the lines for the attractions will all close at 8, but they won’t start herding people out of the park (gently, in a Disney manner) until after the show is over. And the areas that are needed to access the show will be fully available until that time.