I'm not aware of ANY planned changes to AG right now, nor why we would expect anything major, to be honest. It's a pretty nice area tagged on to Next Island with its own character and feeling to it, plus an armour upgrade chain and armour plating from the gorgon event area.
What WAS speculated was more in the way of time travel areas from NI, but not as an addition to what the shares cover. Advances to AG would thus be better bps and uses for the AG mob mats over time, but NI devs would probably want to secure any better bps they are allowed to have by MA for NI main planet (skyripper etc.).
For me, the only way turnover on AG is going to grow is to balance the loots way way way better and to have more footfall on NI itself, similar to Arkadia and Arkadia Underground/Arkadia Moon as smaller areas attached. That doesn't take dev speed, it takes balancing competence and approval by MA. Their discussions with MA over the skyripper 'balancing problems' show that poor decisions may continue to be made in all areas. Personally I think that all planets should get identical stats weapon bps etc, but with local mats that are mostly well available. Players can then choose the areas they like most to play at, while not needing to bother quite as much about which planet has the best stuff.