@EA_Joker
That link you provided to EA's support for child accounts (https://help.ea.com/en-us/help/account/give-your-child-access-to-games-on-their-child-account/) is helpful. But I find it to be misleading information from EA.
EA implies that "child accounts" are a legal issue and that they are simply following the law. But their implementation in Battlefront 2 doesn't do that.
1) They are not looking at accountholder age in Xbox; they are simply using the child indicator. There are many accounts that are designated "child" in Xbox that are above the COPPA age designation (13) in the US. I'd guess most of Battlefront 2's target demo falls in that bucket. My older son certainly does.
2) They are ignoring parental permissions in Xbox, despite EA's own guidance that parental permissions can be used to fix this. You can set access to 15+ and set all your child account permissions as open, but Origin still won't recognize the child account as an online participant. So EA is actively offering incorrect help on this, both online and through their call support.
3) They are ignoring game-level permissions in Battlefront 2 specifically. FIFA 18, another EA title, shows up in Xbox with a game level exception so that child accounts can play the game without problems. Battlefront 2 does not do this.
4) They certainly aren't offering refunds for the significant portion of online content that isn't accessible by the game's target audience.
The reasons for this are readily apparent in my view: EA doesn't want the potential liability of minors playing Battlefront 2 while the loot box gambling accusations are still being kicked around by US regulators. So they've just locked out everyone under 18, the legal age for gambling permissions in the US. It's easy for EA, but it's a terrible indicator of the regard EA has for its customers.
I completely agree that EA isn't going to fix this anytime soon and that it is purposeful, not a bug. Parents can of course set up pretend alternate adult accounts for their kids and access the Battlefront 2 online content. But that is a challenge for pre-existing child accounts with substantial time investment, it cuts around Microsoft's parental permissions system which is actually of some value, and it's quasi-legal. (That last is why I'm not posting how to do that here),
More on this in the Bug Reports section: https://answers.ea.com/t5/Bug-Reports/Xbox-Attempt-to-connect-to-online-error-code-524/td-p/6431848/page/6