There is a workaround to connecting to the BF2 servers if you're unable to connect after the latest patch. Note: I've been able to reproduce this over and over. I start offline each time when I start up the app. Each time I follow these steps, it works.
1) Load up the game until you are in the main menu
2) Play an arcade game (doesn't matter which battle scenario).
3) Kill a few A.I.
4) Leave game (and don't press anything)
5) Once you're back to the battle scenario menu, click the right stick to connect (Note: it will fail).
6) Once you get the error code 721, head back to the main menu and tab over to the collections menu
7) Once there, click connect (Notice in the top left corner the connection animation will start to work).
8) Now you're connected