Today I knew I would have a new villager showing up, so I made a new character to plot check. On the new character there was no new plot anywhere to be found, so I thought I had just mixed up my days and logged into my mayor, and suddenly there was a new plot! Thankfully it wasnt in a horrible spot...
Yes, when I started plot resetting Rosie, her plot didn't appear for the first couple of times and I freaked out cuz I thought I wasn't getting her or something. But then on the 3rd attempt her plot appeared and I got her into the spot I wanted.
If you want to make sure that doesn't happen again - do this: If checking for a plot and there is none, continue and save with that character - then delete them. That way you can load with your Mayor no problem. The next day, plot check again with a new save file to see if a plot appears. Rinse and repeat.
Plot resetting is like multiple universes theory. There is an universe when you get the plot, then you reset, BOOM, universe with the plot. If you want to make sure the "universe" where the plot doesn't appear stays like that, save with the character and demolish their house, it will cause grass deteoration in the house spot tho. Or keep trying till you get the villager you want or the spot you want.
It's just really bizarre how it works sometimes. I've invited villagers to move on from other towns and the next day their plot has been there one moment and the next I can't find it anywhere in town. That happened with Julian actually, completely disappeared. I ended up turning off the ds and loading back up again before it went back to normal and the plot appeared.