They already put a Habsburg emperor on the throne of Mexico once, they could probably have done it again with the central power's help (Assuming that for whatever reason the central powers completely dominated the European theater so much they launched a naval invasion of North America), It's not that much of a stretch to say that they would do it again and take Baja California as a vacation home
Wat
Also how the fuck are Austrians going to conquer California...
https://en.wikipedia.org/wiki/Maximilian_I_of_Mexico
They already put a Habsburg emperor on the throne of Mexico once, they could probably have done it again with the central power's help (Assuming that for whatever reason the central powers completely dominated the European theater so much they launched a naval invasion of North America), It's not that much of a stretch to say that they would do it again and take Baja California as a vacation home
Also, Japan was on the Allies side in WW1.