They’re not saying only Jews should be counted. They’re stating a fact that the Holocaust refers to the genocide of Jews by Germany. From your own Wikipedia link click on “The holocaust” and you can see the definition right there. Under it you can find where “The term Holocaust is sometimes used to also refer to the persecution of these other groups.” As in: this isn’t what it technically means, but people sometimes say this. Sort of like Kleenex when you mean tissue. Or dumpster when you mean waste receptacle.
While I think Zelinskiy is an amazing leader, he’s not infallible. War time leaders, especially when locked into a (even if temporary) stalemate. Sometimes our thirst for constant progression outweighs the tactical advantage of holding and regrouping. Ukraine needs consistent, clear and unanimous leadership from both political and military leaders.