There will be no wipes but if they change for example ore locations or add new ones you will need to start a new Game. But you dont need to. But you will not have the new ores or other changes to the Map. As right now you can find every ore that is planned. So in theroy you should be able to play the whole Game to the End with a current save.
Same goes for some performace Optimization. Some will even apply one saves others that affect the World itself will only affect new Games.
I had the Idee, since you can edit the save fiels with a Hex editor, when they make changes to the Map, start a new world, save, leave the Game a Copy all the Build stuff and foliage removed to the new save.
I have no clue if that works, i need to try it when the first update is out with Map changes.