The HMMWV -the military version of the Hummer- is produced by AM General, not by GM. So it is not affected by the sale of GM's Hummer division, should it go through (Wikipedia states that the sale will be blocked by Chinese authorities).
Also note that only the now discontinued Hummer H1 model was based on the HMMWV, not the current H2 and H3 models.
No, the Hummer was designed as a behind the front carrier, unarmored, for use in a traditional war. Generals always are fighting the last war. And the Hummer and the M1A1 tanks were designed for fighting the Russians in a hot war. The obvious place to have that war is from Germany through Poland and on to Eurpoean Russia.
You sure are not going to have that type of war in the Balkins. Or South East Asia.
You might have it one in the US midwest if Canada attacked the US.
Since not a lot of folks think wars like these are likely in the future, the Hummer has no future.