Exactly. "If you keep some, in 2-3 years it may be worth a LOT more." Or: "If you keep some, in 2-3 years it may be worth a LOT less."
If Bitcoin starts to catch on and go mainstream (there are some early positive signs) then yeah. If the current media fascination and fad fades out, then not so much. There is a possible future in which bitcoin continues to trade amongst a very small population of geeks but no one else cares and the value becomes difficult to sustain. BTC at $1 is not unthinkable. BTC at $10,000 is not unthinkable.
For me personally, I'm going to hang on to my 0.1BTC and possibly buy more and possibly sell some and so on, just for fun. (I used to be a currency trader professionally.)
But for Wikimedia, it just doesn't make sense to hold a speculative asset.