However I'm afraid the newly acceptable term, "intellectually disabled" will soon have the same connotations as the previous one. For years the words referring to that kind of condition have kept changing. "Moron" was certainly insulting, and "mentally retarded" (which means slow or held back) was an improvement over that term. Later "developmentally delayed" was often substituted for that one, although the literal meaning is similar.
I wonder if the new term will include people with learning disabilities, autism, personality disorders, and mental illness, all of which could be considered intellectual disabilities. If so, some interesting legal problems may develop.
As long as the majority of people are uncomfortable with those who are different from themselves I don't think changing the terminology will make much difference. Prejudice usually results from fear and people's effort to assure themselves that they're safe because they aren't like "those" people and never will be.
We've come a long way since children with "intellectual disabilities" and many physical ones were sent away to institutions and their families could act as if they didn't exist. But there's still a long way to go before people with special needs are accepted in our society. Changing that term is one step in the right direction, but it's a very small step.