Boomer is honestly just used as a generic term for older people who are out of touch in one way or another. Millennial was a generic term for young people the speaker didn't like, but it's finally been replaced by zoomer which is more age appropriate, but it took a long time. It's not that people are ignoring Gen X, it's that most of the time when people use the term they just mean older/younger people in general.
TLDR, Gen X is probably lumped in with the term "boomer" (obviously the context matters, but this is the TLDR).