Nope, you don't get it.
1. Not sure why you are now talking about 45+ vs 0-44. The topic is about seniors, and 45+ are not seniors.
2. The median age has nothing to do with it and I'm not sure why you think it does.
You're confusing two different things.
Fact: Yes, there are more seniors now than in 2011. That was never under dispute.
The question is, where did those seniors come from?
You have made two claims:
1. "retirees are the driving force behind the Capital Region's population spike " and
2. "boomers/retirees are officially the largest group of newcomers to this region"
Both of these statements have been proven wrong by showing that the increase in seniors (generally accepted to be 65+) is due to aging of the population, not due to newcomers. Furthermore, the increase in population is due to an increase in working age adults migrating here.
The 45+ age brackets are specific to boomers and retirees for the 2011 and 2016 census periods (boomers were 48+ in 2011, 52+ in 2016). I'd have started my numbers at 48 if we had that breakdown, but we do not. My article was specific to boomers and retirees, but your blog shapes the article as solely about retirees (65+).
Clearly we're interpreting the data in different ways, and we clearly do not agree with each other, but we also don't need to be blatantly picking apart each other's articles in the pieces that we publish on our respective platforms.