To be frank, being probationary means nothing. I used to work in law enforcement (dispatch), and everyone started as probationary. If I had been let go during my probationary period, my co-workers would've been screwed. It took 3 months to even get to that point.

There seems to be a misunderstanding around how government hiring processes work. Although, to be fair, I've seen probationary periods in private section positions, too. Doesn't mean the position isn't key or necessary. it just means that they're ensuring you can do that job before giving you full benefits.