After much ado, and 3 hours of panicking about finishing my Hoenn Dex, I was hoping a tiny note can be slipped in to the article.
It notes that:
If you're lucky enough to be near a Nintendo Event, you can grab yourself an Eon Ticket via a Wonder Spot. You can use this ticket to travel to Southern Island, where the other Lati will attack you when you examine the mysterious egg deep in the forest. So theoretically it is possible to catch both Latias and Latios in Pokemon Emerald.
I can confirm that it cannot be received via swiping the card (as Emerald only recognizes wireless events). BUT, it can work (as expected) with Mixing Records. One thing I did not know, and would have found helpful, is if somewhere, it was specified that the Ruby / Sapphire game with the event needed to be 1st player when mixing.
Small detail, but if added, would be appreciated.