I would like to suggest that you add spectate option for Outland arenas. Since we can already purchase items in Store that were never aviable during retail tbc, we can for sure add an NPC to spectate arenas.
Also another suggestion would be to change the amount of Arena Points rewarded from 3v3 to match the amount rewarded from 5v5, or even bit higher than that. This worked great for other server, where 3v3 became second most played bracket.
Now its your chance to make PvP community return, Outland is still best PvP server out there and other meme servers are finaly getting deserted after majority of players found out they suck.
Some other suggestions:
1) Lower rating requirement for all S3 and S4 items by 100. People that truly deserve them already got full set during original season, people who are willing to buy them for coins already bought them too. You could aspire the rest to push rating for shoulders again.
2) Make 2v2 tournaments event at end of each month for coins (20-30 coins per member)
3) Implement weekly rating decay for teams above 1.8k to make people que in order to not loose rating. (also worked great on other server) To avoid rating decay, team would have to play atleast 10 games that are agaist teams in 150 rating range from theirs. (to avoid people queing for +0 at 6:00 AM)
All sugestions mentioned above are reasonable. Implementing arena spectator cant be that difficult since you got it on your WotLK server already. So if you still care about Outlant a tiny bit, making this miniscule time investment might be worth.