I for one am tired of playing as a straight, white male a majority of the time. I'd like to have realistic variety in games, and it seems we are heading more toward that.

Whatever their reason, I'm glad they changed to the character models for women in MKX. They looked terrible in MK9. They all looked like man faced strippers with bad boob jobs. It didn't realize how bad it was until I went back to MK9.

I agree. The FF XV devs having to explain why the party is all male was dumb.

To address the OP, yes and no.

Anyone trying to utilize their creativity to the best of their abilities usually require a certain vision in mind, whether it be abstract or specific.

Letting trends or dogma from outside point of views effect the original or intended vision can stifle someone's work and restrict their creative freedom.

However, there is another side. Writing from someone else's point of view on unfamiliar or rather uncompelling (to the artist) subject matters can force an artist's mind to expand and take in new experiences (which can potentially strengthen an artist's repertoire).

I know that's not simply limited to gender, race and sexual orientation, but the many facets of each of those fall under subject matter an artist probably isn't familiar with and could use to gain experience in artistic integrity.

At the very least I guess the positive side is that it could allow an artist to be more vulnerable and take in new ideas. Those new ideas may even help an artist to create better written stories or more illustrious art.

No!

You are aware that by saying "can force an artist's mind to expand", you are implying that an artist who doesn't act in this way is limited or narrowminded.

That is the genesis of the problem. 

One must not assume that his/her point of view is superior. An artist has the right to do whatever he/she wants to do without fear of being viewed as narrowminded, old fashioned, limited etc.

No.

No, in most cases I don't think it restricts a developers creative freedom. If a character's race, gender, religion, or sexuality is of no consequence to the game's story or vision then why not include characters of varied backgrounds. But if a developer feels pressured to change the story or original vision drastically in order to accommodate a groups wishes, that's when I feel it would be restricting.

That Tomodachi Life example is horrible btw because in that case you are playing as yourself in that game. So if you happen to be gay or lesbian you can't properly enjoy it to its full extent as someone who is straight could. Nintendo honestly should have seen that coming, I mean it's a life simulation game after all so you should be able to portray yourself appropriately.

There does not appear to be any regulation forcing developers to cater to any particular demographic. So I'm not sure how there can be any claim of restrictions on creative freedom. The only constraints on creative freedom are the market forces of: How much does it cost to make the game? How much can you sell the game for? And how many copies of the game can you sell?

It seems to me that overt homophobia is likely to diminish the sales potential of a game, but big boobies, naked boobies and female characters with unnatural body shapes still helps game sales. So people wanting to promote a homophobic agenda are likely to have their creative freedoms constrained because the market won't buy their shit. But horny heterosexual dudes are still a substantial market segment, and sex still sells.

I'm not aware of games particularly catering to ethnic minorities. Except to say perhaps that white people are an ethnic minority on a global scale (and gaming is a global market), so perhaps developers having to mostly cater to white people is constraining creative freedom a bit.

I don't recall the last time I played a game as a straight, white male. They are fairly rare these days.