Whether a game has cross progression simply doesn't rely on the fact that a company is big or not.
Every game is made differently, some allowing growth for new features, some not.
Note that this game was designed for a much smaller playerbase, therefore the chance of their internal systems not having been designed around cross progression is much higher.
Apart from it being a technical limitation, note that there also are legal limitations included since console companies are involved with it.
Also do note that cross progression was never promised, all we got was a rough timeframe but never an official statement that gave us an exact timeframe of which it would come.
It's difficult to log into an EA account inside the game, so that users on the console can simply switch from one psn to another psn, even the deceasrd rainbox six siege has this function.
Community Manager
