Yes, and no.. Most of us are college-educated, decently-traveled, and for whatever reason, seem to trend from our 40s into our 60s, which means most of us grew up with the Soviet Union/Russia being the big bad guy (and Putin proving that continues to be the case) and we grew up with the idea of not being able to trust the Soviets/Russia. It also means a lot of us have seen a lot of bullshit in our lives (helped by being college football fans). A lot of us have some kind of military experience, or have worked with the government in some capacity (even if just business dealings), have read our fair share of Tom Clancy, etc. novels (a staple in the late 80s and into the 90s), and are well-read (outside of fiction) etc. and so are into this stuff more than most people.
Most of us have also been around on various message boards, BBSes, usenet, etc. going back decades, so we have seen a lot of bullshit, a lot of misinformation, and not just because we are college football fans and used to people pushing misinformation to try and milk $9.95 a month out of us, but it sure as hell helps to be exposed to college football "journalism" and fan sites that are pushing this or that latest recruiting scoop or conference realignment talk or whatever - many of us can smell the bullshit.
So from that perspective, yes, this is an echo chamber in that we have we have a lot of common/shared experiences, even if they weren't identical.
Except that it's hard to put us in any specific echo chamber - I'd say we have a lot broader worldview than most people and we are more than happy to look elsewhere from information - because of our longevity, our interests, the forums we used to communicate online (such as Surly) we've been forced to look at perspectives we might not have considered, and again, most of us are old enough to remember Soviet/Russian propaganda from the 80s and earlier and we see it rearing its ugly head in 2022 and 2023.
We are also used to doing actual research, whether it's academic or business-related, tracking airplanes for potential head football coaches, or even hobby-related. This thread is proof - plenty of us have mentioned going down various rabbit holes on podcasts, books, interviews, etc. in reading about what's going on in Ukraine (including the Australian guy's hour-long YouTube videos doing deep dives on obscure or mundane stuff).
The true echo chamber residents are people like Elon Musk or my Qanon in-law who automatically buy into bullshit that some anonymous person mentioned in a tweet, or older people who get their views from talking heads on TV - these people are looking for confirmation bias and nothing more, either because they can't analyze complex scenarios or thoughts, or because they are too lazy to do so. These people buy into the bullshit Nordsteam conspiracy theory that Hersh is pushing, even though multiple people dug into that story and disproved it quickly. They have the attitude of "Oh Hersh had something to do with Watergate so he's respectable and he's breaking free of the mainstream media and doing his own thing" because, again, confirmation bias - they need to believe him. They don't stop to think that A) we have no reason to bomb pipelines we had already been getting shut down with economic sanctions and B) they should look at what he actually said (or look to people who looked into what he said). The problem with those types is that they are easy to fool, and extremely hard to convince that they've been fooled.