Something important to remember is that even though the intention with games like that is to identify with the character you're creating people don't often play games as they are intended (if they did would modding games be as popular as it is?). So the argument framed in the 4th panel, despite it being framed as invalid or shaky is actually a valid argument because if people are using mechanics in ways that aren't intended, then it's only natural this would be one of them. Let's face it, not everyone identifies with the characters in the game and they may want to satiate their attraction rather than to identify as the character, this is a common sentiment in 3rd person games where the character is being looked at from the outside, AKA a perspective that isn't you.
Another thing about this is aesthetics, because people can like things that are seen as feminine without actually being girls, people like this who identify as male are femboys, and they are valid as they identify. Unfortunately most games out there which have the courtesy to offer the luxury of character creation, don't offer gender-nonconformity as well. So this is another reason to violate intended use case. So 2 and 3 are very much valid use cases.
All in all this isn't the worst thing but I'm not really a fan. There's many reasons someone can use avatars in games that are different from their own sex and gender, the way this is framed makes it seem like it automatically means that you must be trans. In addition this mentality is a double standard since it obviously never applied to the many female gamers before gender selection was implemented as widely as it is now, I mean them playing as a boy doesn't make them a boy now does it. Also the attitude of "oh ho ho that's not very cis of you" does not come across as respecting the egg prime directive very much, but also at the same time doesn't come across as outright disrespecting it.
Gross, flair as NSFW or better yet, don't post this shit on a meme community in the first place.