The celebration scene from "To where and back again"

[Discordrules123 10]

I'm probably not the only one who's noticed this, but it seemed like our heroes have forgotten the fact that there were some changelings currently stationed in other areas of Equestria, including Canterlot itself, so it feels like their celebration was a little too soon. I also can't help but imagine Chrysalis rounding up those changelings for some kind of revenge scheme. If it was possible, then maybe they could have created a scene where the ponies go out to take care of that issue before heading to Equalsville.

[Prospekt 11,020]

I really don't think we've seen the last of Queen Chrysalis. Maybe a future episode could involve finding the rogue Changelings and attempting to reform them before Chrysalis can get to them? That's probably the best way of keeping her from putting a new army together.

[Luigi 7,870]

I agree with Prospekt. Celestia and Thorax should make a pact to find those stragglers so that Deus Ex Machina doesn't happen again.

[Discordrules123 10]

I doubt if they'll make an episode like that but, eh, who knows.

[JH24 385]

You make a good point. I mostly think it will be done off-screen. Those Changelings are most likely higher ranked, very well trained and maybe even coming from an Elite guard. (Kinda like royal commando's) Some may be caught, but most of them will likely join Chrysalis down the road. And I have a feeling they won't be as easy to turn as the Changelings at the Hive.

[Sonic5421 425]

Yeah, Discord took everyone back to Starlight's old village at her suggestion, and no indication they kicked the Changelings taking their places in Canterlot, Ponyville, and the Crystal Empire out first is shown at all.

Did they deal with the Changelings impersonating them off-screen? Did they leave Thorax to deal with them and get them to reform as well? Or did Chrysalis get to them first and retreat with them to plan her revenge on Starlight, the Mane Six, and the Royal Family further down the road?

A clear use of the "What Happened to the Mouse?" trope here, and I hope it is answered at some point in Season 7 or later to help bring full closure to the threat Chrysalis still poses to Equestria since she escaped to plan her revenge once more.