Well, it would be a funny meme :)

But really, it is a name that isn't too uncommon and it isn't as if "heil" is a completely taboo word in German. And he seems the most competent out of all candidates and is the one where we can have the most certainty that he will do it well, which is the most important qualification currently IMO. Even if e.g. Högl could do the job very well, we don't know how well she performs as a full minister and the last thing I want is another incompetent defence minister. With Heil you just have a safe pick.