If you're one of the people affected by the Nintendo Switch's left Joy-Con connection malfunctions, Nintendo's latest statement will be music to your ears. Nintendo has released a statement addressing the issues with the Switch's left Joy-Con, and detailing how you can go about getting the issue fixed in your Switch if you're experiencing the issue.
In their statement to Kotaku Nintendo says that the problem is not with the hardware as it's supposed to be built, but that the problem has come from a "manufacturing variation" that is resulting in the wireless interference in the left Joy-Con. They go on to say that the issue has been corrected at the factory level, so Switch's being manufactured going forward should not see this problem. They also state that they have a simple fix for the issue, if your Joy-Con is affected by this error. Nintendo then goes on to ask that people contact their customer support team to see if the manufacturing error is the cause of your Joy-Con issues, and is offering free fixing of the issue, "consumers can send their controller directly to Nintendo for the adjustment, free of charge, with an anticipated quick return of less than a week."
CNET actually opened up the left Joy-Con after getting it back from Nintendo to see what exactly the fix was, and it turns out that all they seem to have done is add a piece of conductive foam into the Joy-Con to protect its internal antenna from interference. If you have some technical know how and don't mind risking breaking something, you could probably attempt this fix yourself without sending your Joy-Con off to Nintendo at all.