It's not EVEN a plot hole.
A plot hole is an event that happens without a logical reason. We don't even HAVE the event to know whether or not there WAS a logical reason behind it. All we know is the end results of the event, so we CAN'T establish that it's a plot hole. In fact the time skip is a cheap way to AVOID a plot hole.
As I've brought up before as a point of comparison: Ignoring the fact that Rachel was the One True Phoenix and had mastery of it for YEARS is a plot hole in AvX, because the entire conflict is built on the concept that the Phoenix is coming to earth, no one can control it, and the X-Men and Avengers come to blows over how to deal with it (the plot hole being that Rachel CAN control it, and the leaders on both sides in the event would KNOW that). If instead there was an eight-month time skip where ALL we're told is that the Avengers and X-Men came into conflict over the Phoenix Force, leading to Cyclops becoming Dark Phoenix, it would NOT be a plot hole because we don't have the context. All we know is that X happened with Y consequences, but none of the details that would create a plot hole.