Unfortunately to my knowledge, they are just starting to roll out the A50 upgrade in South Korea. While that definitely signfies that will soon roll out to the US, it has yet to be released just yet over here. Samsung tends to roll out updates in waves depending on your carrier/what phone you have.
It's difficult to say exactly when the A50 will get the update here in the United States but we should start seeing it be rolled out soon.
I hope this helped in some small way!