umm... My friend... No.
1. As i mentioned and you seem to now be ignoring, i did state that bringing up the old racial implications of boy was a digression, but it is an example of the word and usage of "boy" being demeaning. If you are unaware of this historical fact, i have to ask how old you are, since it should be fairly common knowledge? And again, i admit it was a digression though one that shows that, yes, as a term, in context it can indeed be demeaning. How's about this as a real world experiment. Go around to any and all businesses and call any employee clearly over the age of 30 whom you have never met beforehand "boy" every chance you get. See how that works out for you. Most people don't do that as a matter of common sense, but perhaps the real world is indeed the best teacher.
2. I don't have a problem with the name supergirl. I do have a problem in a live action adaptation (quite different from comics and animated programming, and even then...) in which the character is specifically well over the age of adolescence and has been cast as such, that said character is still being referred to as a "girl". It is not the name, but again to drive it home, the context. It's a pet peeve of mine, one i am betting a good number of fans of every stripe may share. Not all of course but it's an opinion i have indeed encountered and agreed with in my time as a fan of this material quite a number of times. So... Nope. It's far from just being little ole me.
3. Your position on hawkgirl and hawkwoman does not match up with the history of the character in the least. Please go to any history of the character to understand that of which you speak because you were totally incorrect in your statement that hawkgirl and hawkwoman were not one and the same. They have been (and in the future probably will be again) one and the same, the reasoning has indeed often been in these cases that the name change was due to respect for the character not to be called "girl" and the connotations that go along with it. Thus, again, why sue storm-richards went from invisible girl to invisible woman (she was a mother whom had knocked out the hulk... She deserved to not be thought of as "immature" or in need of guidance, connotations of the moniker, "girl"). Have you ever wondered why marvel through the 90's did not return jean grey to her original code name? Even in the widely seen animated show? She was not known as marvel girl despite being separated from the phoenix during that period (the x-men blue/gold team era). They did so because she was no longer even close to being a "girl" (and perhaps deciding it's a cheesy moniker to begin with, especially for the "extreme" 1990's, though that is debatable). Now yes, there have been various versions of hawkgirl, from the saunders version to the timm show, and guess what? There were people that voiced opinions on those versions ( versions whose existence doesn't somehow negate the character of hawkgirl that then became hawkwoman in some sort of zero-sum iteration of logic.) that were the same as my own, both male and female.
In closing, let me say... Enjoy the new supergirl show. I hope it is good, and that despite my misgivings it does turn out to be something i too will be proud to have associated with the superman franchise and general mythology. But, yes indeed, myself and others find some of the choices we are hearing about now to be ones that we just don't like, and yes, that includes the the decision to name the show supergirl when it's about a version of kara that has long since passed over into maturity and womanhood.