Actually that research is biased,and is done on OPTION school kids..(very selective oral schools.) Not the oral population as a WHOLE...they're just getting better at telling kids who NEED ASL early on,that they need it...They're still getting a plethora of transfers from CID/Moog/St Joesph's at the Special School District ..Yes,the language gaps aren't as severe.....that doesn't mean they don't exist.Very few dhh kids completely graduate/sign off from speech therapy..(and most of them are in it due to LANGAUGE issues not mechanics).also many oral kids still have significent written language issues (reading and writing)....the ONLY difference is that their speech skills are a bit better (like on the level of HOH kids basicly....did you know that 30% of HOH kids still have a lot of the same issues that deafer kids do?
Like it's common for an oral kid to be say 10 years old but have the receptive and expressive spoken language skills of a 5 year old. Also, oral kid's verbal IQs (which measure mastery of spoken language) are still not up to par with hearing kids....if oralism worked then dhh kids would have on par verbal IQs.
Finally I did not say that enrollment was increasing at res schools.....There ARE schools such as Texas School and Rocky Mountain Deaf School as well as some others that have seen increased enrollment (TSD has 500 students this year) There are regional dhh programs....res schools aren't the only options.....I said that the difference is that oral kids(who struggle) tend to now be transferring to their state Deaf schools or regional dhh programs,instead of transferring to Clarke/CID/St Joesph's around fourth grade like in the old days.