Unfortunately, this is an issue that is up the vehicle manufacturer to decide. While there is a proposed rule to require increased compatibility, nothing at NHTSA is getting done in the immediate future and that wouldn't affect older model years either. If your vehicle doesn't work with your car seat forward facing because of the tether anchor not fitting, the options are to continue to rear face until booster age (may require a new seat), forward face without the tether (may increase injury risk), try a different seat (may or may not work/be possible), use an alternate option (such as a Ride Safer Delight Vest), or not transport kids in that vehicle. None of those is a great choice; sometimes there's no great choice. Sometimes the best we can do is make a tough choice between not-ideal options.
This is an issue because the vehicle manufacturer chose not to prioritize compatibility with tethers they knew were being used on car seats. You can call and ask if they have a solution we don't know about, but I'm guessing they don't.