The ONLY reasons they won't ping you is if they haven't seen you for a week or on that given day there is some kind of event going. For example on the day of the festivale, none of the villagers pinged me for anything they just walked around doing the singing emote all day.
Most of the time when ppl make those threads it's because they were a) careless b) TTing accident) c) they forgot/didn't know that if you take an extended break from the game and you don't TT back the time to the date you played last, you should expect to lose a villager.
Just to be 100% certain without question tho I always like to TT a week ahead and create a new character and see if anyone is missing. I don't ever like leaving it up in the air.
So in summary my answer is I'm pretty sure that they will ping you with a few exceptions but if you want to make absolute certain then TT a week ahead with a new character