The squad system is slightly broken. The key problem is that if you join on someone, and that person is in a full squad, you get left in limbo unable to join a squad until that person leaves the squad they're in.* This is exacerbated if you have a party of 6 or more players as when you join the game at least one person is guaranteed to end up in limbo.
The first instance could easily be solved by the game moving a player out of a squad when you join on them (as happened in bf4). It would be annoying, but at least no-one gets left in limbo.
The second problem I suspect will not get fixed as I think that while DICE want to encourage squad play, I think they've learnt from the likes of us** and the CFA that if you can get 3-4 squads together on one side of a server you can really ruin the opposition's day.
* There may be an exception to this as I'm sure I managed to join a squad the other day while in limbo with someone else who was both in my party and also in limbo.
** I've had complaints on the EA official Friday night BF server while EA reps, DICE employees and CFA players were on, that *we* were stacking...