I'm wondering if its a coincidence that this was posted the same day as the 2.5 trailer, which was heavy on the archaic speech by way of narration by Urianger and the dragons. The dragons are old, so you can't really blame them for using old speech patterns; it shows their age. Urianger, though, that's part of his very character. Louisoix himself said to forgive the guy for having spent more of his life reading old tomes than speaking with modern people. His idiosyncratic speech and social awkwardness have even been utilized by the storyline several times. To complain about Sharlayans (Minfilia included, as she shares in much of their aged research materials) is like complaining about Baderon, whose pirate-like speech is nigh-on unintelligible half the time but really serves to draw you into the world. I'm not quite sure how that breaks immersion, because it heightens mine. Granted, I'm thinking less, "I have to stop and try to figure out what this means," and think more along the lines of almost being in character: