Ok last chapter I was saying it's still possible to connect to the WiFi servers for the DS. It's actually pretty simple. It doesn't really matter what kind of DS you're using- it can be a DS or a 3DS.

Open up the internet settings. For whatever internet source you're using, go into the "Change settings" option and find the DNS option. It will most likely have "Auto-obtain DNS" set to yes. Pick no and then pick "Detailed setup". Tap on "Primary DNS" and enter this number:
178.62.43.212
Hit "Save changes" and do a connection test to check that it's working. Bam, that's all you have to do.

As far as I know, this works for both gen 4 and gen 5 games, as well as other games that had Internet features. It doesn't work for emulators, though.

So there's a website where you can see all offers on the GTS. In White 2 my name is Dawn, if you ever see an offer from someone by that name. It's probably me. I haven't seen any other Dawns on the list.
https://pkmnclassic.net/gts/

[There should be a GIF or video here. Update the app now to see it.]

Here's an old video on my channel. Idk if you can see it on here, but I mentioned these steps in the description. I might make an updated version and put it on my gamer channel.