I'm going to ask this question one last time.

After the amiibo update, is it possible to not let any of your villagers move out for a really long time(longer than ten days) as long as you do this trick?

-Get someone to ping you for moving
-Deny
-Save and Quit right after
-Title screen
-Don't play
-Exit game

Would I still be able to play other games than New leaf afterwards for the trick to still work?

It still works.

Make sure to deny the ping!

It works like a charm

I can also confirm that it still works. I have my towns of AHS and Folsense on hiatus using this same trick, and I recently used it to move my main town forward into real time.

Yeah, it's kinda weird, but you can basically keep your Dream Villagers forever using this trick without using Amiibo cards. If you came back from a really long hiatus and forgot to do this, look into your activity log to find out that date you last played ACNL, now your activity log may be messed up if you time travel using the system clock a lot so try to remember a rough estimate of when you last played as well. Using the system clock, and without loading the game, set it back to the day you last played. Load animal crossing, and no one should have left. Then, to get back to real time, simply wait or time-travel day-by-day until a villager asks you to move, (make sure you're on talking terms with them). Then once you deny, go back to the system clock and place it back into present time and voila, you'll have bed head but it's better than losing a villager. If you don't care about your ACNL alligning with present time than you can use the in-game clock instead of the system clock in the last step, just make sure to use the system clock for that first step and never open your game until you do.

I never even knew this trick existed! Glad it still works though, maybe I should use it sometime so I don't have to worry about villagers poofing on me.

Hey nice, thanks for sharing this trick, glad to find it's existence and the fact that it still is working!