You are correct pretty much on all this. I used to measure just how big a game was (and amped up) by if we were standing. The first time I remember it happening was the first home playoff game in 25 years or so. 1/1/89 vs. OIlers. We stood the whole game.
I'm sure the 90s playoff games, we did as well.
And, then we stood for the Cowboys Monday Night game in 2007. That was as amped up of a crowd as ever and it made sense.
It also made sense later that year, when the Pats game got flexed on SNF...............Until we were getting destroyed and I'm like "Why are we still standing? It's 83-0"
Ever since then, it's been standing for almost every game all the time.
Except for our new 110s, where we stand most of the time - until yesterday, where we sat most of the time.
And, yeah - walking in Thursday night, I'm like man, we are in the top 10% of age right now at this gate, easily.
In our area, we're about the median age, though.