This stuff "just happens" over the course of literally millions of years(from your own links). Not a couple hundred.
I was not assigning fault or commenting on timescales or any coincidences, but pointing out this is likely spilled milk at this point.
Our species will need to adapt to survive, there is no going back to pre-industrial times (or even staying at 1990 carbon levels, as if that would have helped). These things eventually happen and we will need to deal with it eventually.
Note that a few methane plumes is not going to do anything on the timescales of my lifetime either (as many scientists have pointed out, this magnitude of methane plumes are likely to be eaten by bacteria before it gets into the atmosphere), but if large scale methane calthrate deposits (which these are not) were to actually to start a massive release at this point, there's not much we can do about it
Unless I'm mistaken, we really don't have much ability to control things on a geological level yet (and no blowing up all our thermonuclear arsenals to create nuclear winter does not qualify as control, it's basically an uncontrolled experiment). It may be premature to say that any efforts will likely be futile at this point because little is known about this phenomena in specific or climates in general, but it seems to me like we are at the mercy of our planet on this topic (as we always were)...