Let me preface this by saying I fly for work.. a lot. Before Wuhan flu I made diamond status with Delta. I often get upgraded to first class automatically when I fly.
Recently, because of specific state restrictions, I've been working from the office with customers over video instead of taking a hands on approach but sometimes you have to go.
Today, I flew back from DFW to ATL. I saw roughly 500 soldiers in fatigues, spread out through check in at DFW. Didn't think anything of it.. I've seen military flying commercial before, usually natl guard. I haven't seen quite that many before but still, didnt think anything of it.. until I landed in ATL.
Every other body in that airport was sporting fatigues. I've never seen anything like it. Something big is going on. I'd estimate 2,000 soldiers in that airport at the time.. but there's no way for me to know for sure.
I've been flying almost every week for the past 6 years, never seen anything like this.
Taking weapons depends completely on what sort of detachment they belong, where they are going, and what the requirements are at the receiving location.
I was in the military for 24 years and can tell you for fact some bases require incoming personnel to carry their own weapons. This is typically because the gaining base has no long term personnel to maintain a proper armory assigned to the base. It's more of a "We hold your weapon while you're here" sort of arrangement.
Now, this happened a lot more when I was in SpecOps for 6 of those 24 years (we took our weapons everywhere), but it did also happen in "normal" mil deployment to places like Kuwait.
It isn't "unusual" by any means, just not "normal" to see...again, depending on receiving base requirements.
From my personal experience, weapons were always shipped ahead of us and none of us personally took them to be checked in.