Well... no, I haven't done research on the matter. Have you? I guess in some severe cases, sure, people will be somewhat traumatised, but very rarely. It's more a case of "I want to avoid this person" rather than a more traumatic "I can't leave the house today because I might get my neck snapped".
Yes I have! I'm also someone who suffers from trauma with first hand experience, which not only gives me the upper hand here but has also given me even more incentive to do my research on both what causes trauma and what trauma can cause!
It's absolutely not a rare case at all and it is an asinine claim that victims of bullying/abuse don't fear for their lives at some point. It's especially apparent in LGBT people, people of colour, and people of certain religious groups. Speaking from a personal standpoint I've lived in fear of
literally just looking at other men in case of being perceived as predatory and "lol gay men are pedos" "lol gay men are creeps who want to r*pe other men" jokes absolutely did not help. The sad part is this isn't even a crazy reaction considering the amount of violence gay men/boys face from straight men/boys every day. I still get scared being nice to men in person sometimes. That fear is trauma and is a pretty universal LGBT experience.
On another note for an even longer time (most of my school years to be exact) I told people I was white because 90% of the time I said otherwise I was asked if I had a bomb, if I was a terrorist, if I carry a knife, etc and once again, "brown people = terrorists" jokes are part of the blame for this.
Jokes don't have a very high chance to cause trauma themselves but they can absolutely both partake in it (depending on the severity, how often they're made at their target, things like that) and they can
definitely trigger someone's already-there trauma.
To admit you haven't done your research and then make claims like this is absurd and I don't want to discuss this further with you, and I suggest you stop discussing it with anyone else as well. I also suggest you stop using "triggered" when you mean "offended, upset, angry, mad" because "triggered" is 100% a mental illness term that deals mostly with trauma which, as you said yourself, is a topic you don't have much experience in.