It's not just white men, though white allies to the LGBT community are certainly influential. There is a wide-spread movement to be more inclusive in (almost) ALL social sectors, which includes the black community. To be blunt, trans-activists of color seem to hold the most capital and power within these advocacy groups, as they always bring up their identity and leverage that to amplify their voice.
LGBT movements aren't specifically targeting the black community, though. Their fetishization of intersectionality makes it impossible for them to even be that critical of the black community, so all change must be done on the basis that (primarily white) American or Western society is the thing that's actually flawed. LGBT advocacy usually attaches the phrase "white supremacy" to the opposition, and hyperfocuses on white critics rather than black (or other) ones. I'm sure you'll get some who might admit to some homophobia or transphobia within the black community, but the thought of it does cause more than enough to shriek in horror for considering that because of a belief to not criticize other people they consider marginalized.
As for the Jews: While many do come from communities that were established in Central to Eastern Europe, do realize that the progenitors of those communities have been shown to be of Levantine (or Israelite) backgrounds. There was some intermarriage between them and the neighboring Europeans, but mostly their genetics today are unique enough to actually be noticeably different than surrounding, purely gentile populations. Whether or not this makes them "white" or not (especially since a lot of people consider the Levant part of the "white" area) is up for debate, though historically they lacked this designation and were treated as non-white. Even today, if the Jews are put into negative circumstances, they're treated as a non-white people. The same goes with Asians, essentially: If they're in a good position, "PoC" status or considerations are ignored; however, if they're in a bad situation, it's racism inherent in society.
Ignoring that the concept and identity of Jewishness is NOT dependent on blood ties (thus voiding the idea that the Ashkenazim are "fake"), the Ashkenazim still show descent to the Israel area through genetic studies. The group that is most similar to them are the Sephardim, the Jews of the Mediterranean who have been in communities that often were geographically isolated from these Ashkenazi for the better part of two millennia. Them, and many of the Mizrahi (Jews of the Arab world) show too much genetic similarity for it to be a coincidence. They're all of Israel. The black men kidnapped to build the pyramids is a false narrative, especially since the Jewish slaves weren't used to build the pyramids we know today. They were likely used for other things. Still, there are legit black Jews in communities like those found in Ethiopia, and they're not going to agree with you on this matter.