come out of the blue (vp)

Their news about emigrating to Canada came out of the blue.
The email from the long-lost friend came out of the blue, bringing back memories of shared adventures.
Her decision to switch careers and pursue a passion for painting was unexpected and came out of the blue.
During the meeting, the boss's announcement about a company-wide restructuring came out of the blue, leaving employees in shock.
The invitation to the exclusive event came out of the blue, and he couldn't believe his luck at being included.