Nintendo issued and official statement on complaints of the left the Joy-Con having synchronization issues:
The statement, which was sent to TIME said the following:
“The number [of Joy-Con replacement or repair requests received] is not significant, and is consistent with what we’ve seen for any new hardware we have launched.”
It seems like Nintendo is monitoring the situation closely. We will see what their next step is, but from the looks of it, they do not seem worried that it’s a widespread issue at this time.