The US MU8000 is the MU7000 here. Main difference between MU6300 and MU7000 (EU) is the addition of the 120hz panel on the 55+ inch versions.
There are also different panels used in different regions too. In the USA the MU7000 (our MU6300) comes only with VA panels. In the UK and EU sometimes they come with a Samsung IPS panel instead.
Samsung have nightmare model number naming schemes in different regions and are terrible at putting different panels on the same tv.