With completely wireless earbuds, the rule is: when the battery fails, they have to be disposed of. Not so with the Fairbuds, that allow you to replace batteries in just a few seconds. Combined with a repairable design, the earbuds should therefore have an extremely long lifetime.
The EU is a relatively large market, and it wouldn’t make economic sense to develop and produce EU-specific devices. I’m pretty sure you’ll also be seeing replaceable batteries.