Thanks for your council.It is not normal for the break to not be announced ahead of time.
I don't pay too much attention so I'm sure some NYEEEEEEERD can correct me if I'm wrong, I don't think breaks are normal unless a Story Line has ended and they are starting a new one. Publishers don't want people having their habits. Less so because some comics are sold via subscription and not shipping a title means subscribers would be rightfully pissed. In this case, very likely the Marvel Star Wars subscriptions run Jan to Jan, not shipping the Jan release means you just bill everyone 11/12th what you would have normally.
Usually any schedule disruption can only mean invasion is a title changing publishing schedule because of declining sales; move a book from weekly to bi-weekly or monthly, move a monthly to semi-monthly - lowers the cost of the subscription to keep subscribers hooked, makes it a less costly pick up, you can start shifting writers & artists to other projects. Basically supply and demand.