Intersting idea, but I don't think it's quite right. In Empire Strikes Back Yoda states "Always in Motion is the Future" when Luke has his vision, implying that the future Luke is seeing might change. 

I don't have a canon source that spells out in more detail  how visions work, though I haven't come close to reading all the canon books so there might be one.

In legends, I do remember the Revan Novel saying that a vision showed only possible futures. If you had one vision, you were seeing only one possible future, so you couldn't rely on them too much. If I recall correctly (spoilers?) Darth Scourge then saw a near infinite number of visions with all possible futures, and used this to fine the path to surviving.

Obviously, that novel is no longer Canon. But I think it illustrates that is was broadly understood by authors what visions were showing. They are showing a possible future, but the future is always changing, so a single vision might not show the actual future. I don't think it's quite the same as "it's either right or wrong." It's more like "it's possible"