I think you're confusing who is, or isn't, at risk
in the context of the TV show and who might be at risk
if the events were happening in the real world. (You're also assuming -- perhaps correctly, perhaps not -- that every changed event in the past would cut a wide swathe through the population of the US, but that's an entirely different issue.)
I was talking about what threats a
real world organisation running a time travel project (one involved in altering history**) might consider guarding against. I strongly believe that it would keep information about its activities, and the effects of its activities, as locked down as it could, in order to minimise problems amongst its workforce (who might react in the way I suggested) and from anyone who both felt threatened and could do something about it (such as the government).
It isn't as if there's any other way to find out if something odd was happening, such as people disappearing, or appearing out of nowhere: no-one, other than those in the time machines, can tell when something has changed. Even the time travellers only find out by comparing their (unaffected) memories with the reality of the world to which they return.
So I stand by my original comment: as few people as possible would be allowed to know what was really going on, as doing so reduces all sorts of risks , including the one I mentioned (an employee deciding that it would be better for everyone (including themselves) if time travelling died a quick death).
As for the TV show characters.... If they lived
in the real world, and Rittenhouse's effort are directed specifically at events in North America (as opposed to Flynn's activities, which are rather less predictable), certain of them might not be at very high risk at all. Connor Mason is British and so is unlikely to be affected by the changes being planned by Rittenhouse (not to mention that Rittenhouse -- and Flynn -- would be rather keen that he didn't cease to exist). It's also quite likely, though not guaranteed, that Jiya is a "second generation" American, who may, therefore, be at reduced risk. And in the show, Jiya's "visions" are likely to be important, so her character will likely persist for most of season two, if only because of
Chekhov's Gun.
** - Why else is Rittenhouse funding the project if not to alter history to its own benefit?