By avoiding the word, you avoid insinuating the target's gender is part of the issue, and/or avoid insinuating that the target is effeminate when they "should not" be, i.e. you avoid homophobia.
A screech is a high pitched sound, nothing more unless otherwise indicated.
I see a lot of people with no knowledge or experience with this common usage. That's fine, but it's arrogant to assume things you don't know are nonsense.
Interestingly the examples in both the entry from Oxford that Google brought up when I searched the term, and the second example in the Cambridge dictionaries are both boys doing the screeching. The other examples are inanimate and screeching describing the experience of tinnitus. So it seems the UK is similar.
So potentially for much of the English-speaking world this term wouldn’t bring up thought of any kind of gendered slur. So it goes both ways - just because something is the case in your region doesn’t mean it’s true across the board.