That information probably won't be made available until Heavensward goes live unless it's something that will get mentioned in the patch notes. However, there is a trend of having each clan weigh more towards the physical or magical attributes. Based on the lore provided I'm taking a guess and saying that Xaela will have comparably higher STR, DEX, and VIT while Raen will be more focused on INT, MND, and PIE. How those attributes will measure next to the existing races is harder to say.
Just for fun I went and had a look at the racial attribute for the existing races and noticed some interesting things.
63 | 57 Sea Wolves
58 | 62 Hellsguard
65 | 55 Highlander
60 | 60 Midlander
60 | 60 Wildwood
59 | 61 Duskwight
63 | 57 Sun Seeker
56 | 64 Moon Keeper
58 | 62 Plainsfolk
54 | 66 Dunefolk
STR 20+ Roegadyn, Hyur
DEX 20+ Elezen, Miqote, Lalafell
VIT 20+ Roegadyn, Hyur
INT 20+ Elezen, Lalafell
MND 20+ Roegadyn, Lalafell
PIE 20+ Miqote, Lalafell
The numbers in the top section are the totals for each clan's STR, DEX, and VIT compared to their INT, MND, and PIE totals. Some interesting things to take from it such as how Midlanders are one of the most balanced with an even 60/60 spread, but when directly compared to Highlanders their magical attributes are higher by a sizable margin. Neither Lalafell clan is particularly strong in terms of physical attributes, but Plainsfolk are less heavily screwed. Elezen are the most well rounded race by far with Wildwood being on par with Midlander's 60/60 spread while Duskwight are only very slightly tipped towards the magical end. These numbers are rounded averages, but still interesting for seeing how they compare against each other.
The bottom section are what I like to call "racial strengths." I looked at each race to determine which ones had a score of 20 or higher in each attribute regardless of clan choice. When measured in such a way each race had at least two racial strengths, though the exact number of strengths per race wasn't consistent with Lalafell having four to offset their low STR and VIT.
What can be taken from all this in regard to Au Ra? Who knows! Like I said I mainly went through this out of boredom, though it may be safe to assume Au Ra will have at least two racial strengths like the rest. What those could be, as well as their attribute distribution as a whole, one can only speculate at this time.