The biggest bottleneck for the PVP Arena on Beta is that there aren't enough participants in certain ages.
On the live markets with more players, this shouldn't be a problem.
According to foestats.com - Beta has a greater number of fighters (5100+) when compared to most live servers in the US (+/- 500). In fact, A1 is the only world with a notable more than Beta, the rest tend to either be similar or less. I checked several other regions (EN, DE, IT, SP, SK) and the German region was the only one that had significantly more active fighters than beta.
...And when you compare to other less active regions like, lets say AR2, you're looking at 1100 active players and 800 active fighters, That's ~15% of the total on beta... "Live markets" doesn't really hold up. Not sure if this is going to be released in all regions, but it could just be that overall the players that have tested it don't really like it, and it's a failed idea. No shame in that, Google and Apple have had tons of failed ideas, and knew when to cut their losses and start spending time on thing their userbase wanted. So....
Can we please have our PVP towers back?
Edit: Seems like fighter count fluxuates a good amount day to day. For US servers, it looks like 90% fall within the 500 +/- range of beta. That's only 10% difference from Beta to Live. 10% more (or less) fighters is not going to change the matchup queue.