I personally think that PSO2 New Genesis is a new type of game advancement in the MMOverse.
We could call it an evolution. /insertdigivicesounds
Now, it is undeniable, as Zizel very well put, that PSO2 New Genesis is a new game, and this is based on the fact that if we were to take away the connection to pso2 and data transfer, it would still stand on it´s own merits as an amazing game and be called PSO-3 validly.
However, and i think this is very important.
It is just as true that the connection exists, that the plot follows EP6/PSO-2´s ending, and that all the connections, data transfers and character sharing exists, and that upon fulfilling some conditions, our weapons, units and mags will be waiting for us.
Not only that, but they have just revealed the game, for all we know, there will be even more connections to be revealed later as i very well doubt that they already placed all their cards on the table, and there will be more to hype to in future trailers, as the game looms nearer.
Furthermore, and as i have explained in the original post, there are a lot of animations, gameplay mechanics and overall action that seems to have been taken from EP5 and more commonly EP6.
And furthermore, they have already stated that the engines and improvements used for PSO2NG will also affect PSO2 to an extent and the game will be improved because of it, to bring them closer and make them more compatible.
Thus, why i prefer to call it an evolution and not an expansion or it´s own game.
And yes, it is quite obvious that the only reason why they did not just decide to make Phantasy Star Online 3 is because PSO2 has been SEGA´s salvation and it´s golden egg Goose, and they would never dare to upset the community and risk lost profits.
PSO2 is way too popular and works way too well to risk sinking their own franchise like the original FF14 1.0 did in case the game is not as successful or the new open world and gameplay proves not to be as popular for some reason.
With the current model, if for some reason PSO2 NG were to tank, they could just as quickly focus on PSO2 more and leave PSO2NG as little more than a side-game or allow the fans to stay invested while they fix NG.
But ultimately the reason does not matter, because it still offers and allows what it does, so you cannot simplify and ignore the expansion-like features, because ultimately they are there too, just as much as it´s own merits as a game.