I was plot resetting another villager but want to take in a different one. Can I go back and invite the new villager on the same day and have them move in instead of the first villager I invited?
If you've started plot resetting, just go on your Mayor character and go back to the day before and the villager you were plotting will not be plotting anymore, it'll be on the day you invited said villager in..
So yes, you can go and invite a new villager in and plot that one instead
(I know this works because I tried this and was able to set up a new PWP to stop a villager I was trying to plot from plotting somewhere)
I don't even think you need to go back to the day you asked Fauna to come in, you can go to the day before ('cos she wasn't plotting then obviously) and it should be fine