I want to be clear that it matters whether you were actually talking about the Holocaust. If you were using this as an analogy, about anything less traumatic than the actual Holocaust under Nazi Germany, then I would argue that it is anti-semitic, because it belittles the degree of horror that occurred. Don't compare other things to the Holocaust, that's shitty.
The following assumes you were actually talking about the Holocaust (EDIT: or something equally bad):
Does it erase Jewish culture, history, or trauma? No, it's clearly doing the opposite of that: affirming the trauma.
Does it dehumanize Jews? No. It's neutral to the humanity of Jews, except insofar as it's clearly meant to affirm the horrors of the Holocaust, which dehumanized and destroyed Jews and Jewish culture.
Does it perpetuate a harmful stereotype? Nope! It might be considered a stereotype that Jews know Hebrew, but it's not a harmful one, and it doesn't make the claim that all Jews know Hebrew in any case. In fact, it strikes back at the idea that specific facts about Jews are even relevant to the conversation about the Holocaust.
Most likely--if you were in fact actually talking about the Holocaust--the person you were arguing with just wanted you to go away, and gave you a bad faith rebuttal.
Edit to add: OP added context, and this conversation was about the Uyghur genocide. Clearly, the intention here was not to belittle the horrors of genocide, since it's actually a conversation about genocide. Not anti-semitic.
I'll go against the grain here and say I do think it's antisemitic, for precisely the reason outlined in the parent comment, even though they themselves are also giving you a pass.
The genocide against the Jews, the Holocaust, was a situation where they were rounding up every single member of the ethnicity they could find in order to exterminate them.
Even though we use the same word genocide for the Uighurs, no credible authority I've ever come across is alleging that is what is happening in Xinjiang. Uighurs still openly populate the province and roam the streets publicly.
To compare them like this is to directly downplay the Holocaust in order to make a point on the Uighurs. In fact, I'd also say the widespread use of the word genocide for the Uighurs is the same, for reasons we're seeing from the reactions of everyone else in this thread.
That's fair as a definition of genocide, though it isn't the way I'm used to understanding the word.
Precisely because of the differences though, I'd also find it in poor taste to make comparisons been the Canadian genocide against indigenous peoples and the Holocaust.
It's a weird thing to compare. What's worse for a people: an incredibly traumatic experience that shapes a culture for generations to come or an incredibly traumatic experience that shapes a culture for generations to come?
Sure. OP posed an interesting question and I liked having the opportunity to deconstruct it. Language is complex and depends heavily on context, and I'd love it if more people understood that.