since it challenges the model of random uncorrelated events.

Not by much, though, since there's Poisson clumping (do planes crash 2 at a time?).

That's the problem with OP: yes, in some strict sense, there will be an epsilon increase after a plane disappearing. But is this increase remotely relevant to any decision? I strongly suspect that if one attempted to formalize it, the contribution of one MH370 incident out of a century of aviation is so small it's overriden by small details of the prior or model or approximations.