Looks like "iffy" is the answer. http://www.cnet.com/news/tizen-wont-be-coming-to-samsungs-older-smart-tvs-ces-2015/ covers this but you must call Samsung to see if there is a kit coming out.
Frankly, I find Samsung's smart systems to be not that attractive. Sorry Sam, we know you worked hard on it but too many issues and then there's your PIA.
Bob
will we be able to upgrade our 2014 hu8550 model tvs to tizen?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic