When they rolled that out it was easy to wonder what would happen in a few years. If Netflix or Amazon don't update their apps for your model, then the app may vanish.
I'm sure you read the warranty and how it disclaimed that such would be around forever.
Nod to another Fire Stick on Box.
As to speaking to Samsung, since they don't write the app, they are not going to fix it.
I've got a 4 year old Samsung UE32D6530WKXXU. Previously I have been watching Netflix and Amazon via an Amazon Firestick but my daughter has taken it to her place.
The TV is connected to the Internet no problem and Netflix and Amazon are on the menu on Smart Hub.
When I clicked on Amazon all I got was a black screen. I read some of the forum and updated the latest firmware. I then got a message saying Netflix was being deleted !
Amazon was still a black screen and I cannot get Netflix in the Samsung App store.
I have done the 8.8.8.8 and 8.8.4.4 on the DNS but still nothing.
It is the weekend so I cannot speak to Samsung until Monday.
Help please.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic