Is there a name for this phenomenon in general? Your phrasing is quite clear but apparently novel, and I think it happens a lot - anti-war clergy don't apply to be military chaplains, so soldiers and commanders hear biased opinions of whether their work is incompatible with their religion compared to civilians of the same faith; people who don't think self-driving cars are a good goal tend not to apply for self-driving car companies; people who think on-prem is better than public cloud tend not to apply for companies that are all public cloud; a company that is known for a certain work culture will tend to get applications who don't think that culture is hostile; etc.
Yes, it's very much like "adverse selection" in insurance; @pdimitar mentions some specific cases of it, but I think the most general might be "speciation" or "group selection".[1] I'm not sure of a non-biological term.
"Filter bubble" is almost right but some of those seem somewhat intentional - the phenomenon here is that even if a porn studio wants to have its employees' prudishness reflect the general population, it can't. Even if the military wants to hire chaplains whose views on just war reflect the general population, it can't. You can usually turn off a filter bubble and you can usually actively avoid self-selection because you're doing it yourself: the phenomenon here is that the selectees are doing the filtering for you.
