That scenario is a pointer to the fact that long term Bitcoin investment is not necessarily determined by length of time, but by the positive difference between the current price and price at the time of purchase. Evidently the technology is still evolving and the right thing to do is not to conclude all too soon what the future holds for something that is still taking shape. To that effect, following the developments in the market and the industry would serve as better guide to what decisions an investor takes.
It depends on the targets you set for yourself. If your goal is to buy at $1000 and to sell at $2000 where you approach it as a long term investment, then it can be seen as such until your goal is met. If the price happens to hit $2000 6 months later, your goal is met and thus you can close your position. From there a planned long term investment indeed doesn't mean it's really long term.
For me personally I don't really focus on targets at this point, but put confidence in what Bitcoin has to offer in the long term. I make sure I benefit from short term fluctuations to increase the number of coins that I have, while on the other side I keep my cold wallet coins until I see prices of at least $10,000 per coin. And then I will just cash out a certain portion, definitely not everything. I want to remain holding a good portion of my wealth in Bitcoin.