Your meaning here was not clear and I suspect this was your intention all along.
Now, what is the phrase "some Mexicans are rapists" supposed to tell us? You could replace the word "Mexicans" with any nationality in the world and it would still be true, so how is this a relevant thing to say?
You could replace "Arabs" with most other ethnicities and it would still be true.
You could replace "gay people" with straight people and it would still be true.
As for "black people commit more crimes", this sentence is a comparator so adding "some" makes an already unsubstantiated claim even less clear. "Black people commit more crimes" is an incomplete sentence which needs to end with "than [comparator group]" and be backed up by verifiable data. "Some black people commit more crimes" doesn't make any sense whether you include a comparator group or not, because "some" people from all ethnicities commit more crimes than "other" people from all ethnicities, so this actually tells us nothing at all about how many crimes are committed by black people.
As for "gender critical people are transphobic," or even "some gender critical people are transphobic", you don't appear to understand what gender critical actually means, so neither version is meaningful.
As such, only the first three become facts by adding the word "some" at the beginning, but they are not meaningful facts.
And the latter two make no sense whether you add the word "some" or not.