The word "guys" is no longer gendered. A woman could walk into a locker room full of naked women who all clearly have women parts and say "Hi guys!" and no one would bat an eye.
The word "pimp" now has two fully distinct meanings that can only be discerned via context.
1) (noun) A person who manages prostitutes, or (verb) the act of managing prostitutes.
2) (adjective/adverb) The state of being totally awesome, extremely impressive, unnecessarily expensive, or a combination thereof. A thing or action may be pimp or pimping (both have the same meaning). In the same vein, one may "pimp" (verb) an object by improving it so that it becomes pimp.
Use of the word "pimp" in the second meaning does not constitute a politically-incorrect endorsement of prostitution, nor the slapping of prostitutes. Pimping is not cool, but being pimp is, if you catch my drift.
Similarly, the word "bitch" has a variety of meanings. It is possible to call another person, perhaps one you have defeated in one on one combat, your "bitch" without being misogynist or demeaning to women in general. However, calling a woman a bitch for her behavior is mysogynist, and you deserve the retaliation you have coming to you, dickwad.
So those are a few words where the original meaning might have been a bit offensive, but they now have a new meaning which is not. Unfortunately, there are words that some people think also have various meanings, but they really don't.
For instance, "rape" only has one meaning, and it is a horrible meaning that should be taken seriously. Sorry, but if you're losing in Alterac Valley, you aren't being "raped", poor baby. It's insulting to anyone who has actually been raped (and there are a LOT more of those people than you think). It's similar to saying "We're being Holocausted", because it cheapens something that is actually pretty terrible. It's a lot like Godwin-ing a thread by comparing someone to Hitler. They aren't anything like Hitler, so at that point you can no longer be taken seriously.
Admittedly, that one is a minor quibble, and not really that insulting. I mainly mention it as an example of a word that does not have any secondary meaning the way bitch and pimp do.
The most egregious example is the use of the word "gay" to mean "bad". "Gay" is an actively-used title for a real group of real people who are unfairly discriminated against in our society. Equating the name of that group with everything bad and negative is not cool. No matter what kind of blather someone may make up about "it's free speech" or "it's just a joke, lighten up" to feebly try to defend themselves, there is absolutely no excuse for using the word that way. Using it that way at all means they are a bigot, and a bad person. If the person isn't a shithead then they'd never find that usage of the word humorous in the first place, so the "it was a joke" excuse doesn't even begin to fly.
Imagine if other groups were equated with "bad". Would it be a good idea to go around saying "Man, we wiped on Gruul again, that's so black!" or "AFKing in AV is jew!"? Because that's exactly what's going on.
In an MMO context, if you use "gay" that way, then intelligent people are going to shun you and decide you must be a child who isn't worth their time. It is in your own self-interest to refrain from using the word that way. That usage will reduce your standing with the type of people you want to have on your team (smart, good players whom you can rely on), and it will only increase your standing with bad players who are also immature people - the type of people who will ninja items from you or clean out your guild bank and server transfer.