was wondering the same, they posted this on their FB 20 minutes ago:
Dear Raiders!
Since the current state of affairs in the Classic Arena raised various concerns, mainly as to Platinum Tier and the ability to progress in general, we want to give some updates on what we're planning to do to improve the situation.
1. Arena Points re-balance in Gold 5 and Platinum Tiers - requirements to reach both Tiers will be lowered.
2. General Arena Matchmaking adjustments. The changes will concern tweaking the matchmaking in Bronze and Silver Tiers. In addition, we will improve our system that prevents players from being demoted from the Gold Tiers too rapidly.
3. Progress Missions. Several Arena-related Missions will become easier to complete.
The first 2 changes are coming to the game this week, and we'll give you more detail on them closer to their release, i.e. one of these days. As for the changes in the Progress Missions, they are on the way as well, but we’ll release them in a distinct patch a bit later.