Hey, here’s a quick easy breakdown.
Saying “rest in peace” instead of “may their memory be a blessing” about a Jewish person: a bit of an irritant, as it’s Christian normativity in the midst of mourning, but generally taken in the spirit it’s intended.
Accusing Jewish people who explain that we don’t say “rest in peace” of trying to control the narrative or of telling people they’re mourning wrong or generally of acting in bad faith: at bare minimum it’s incredibly insensitive, but it’s really hard not to read it as an antisemitic microaggression as well.
This applies pretty broadly, I think, to many cultural practices. “Be decent to people” is not that high a standard. If you don’t want to question or even consider how your default is Christian and white and that’s invisible to you, that’s your business and it’s not my job to fix it, but not starting an argument about why that shouldn’t even be brought up costs $0.00 and will make you not look like an asshole.