I feel you, but I think you should understand that we don't speculate out of sexism. It's just simply that there aren't many female third party characters to choose from. I'll happily take Lara Croft over some characters on my roster. But beyond that, you almost have to actively force a female pick.
But if you really want a female character, I would suggest picking one you really like and run with her. We won't judge your pick. It just seems so disingenuous to request "female fighter". I didn't pick Spyro because Smash lacks quadrupedal fighters; I picked him because I genuinely believe that he belongs with Crash in Smash Bros.
The usage of "forced" bothers me a bit honestly. Because Sakurai doesn't work on just visual variety for the sake of it. Bayonetta wasn't added simply because she's a woman. She had very unique gameplay traits, Bayonetta 2 was Platinum's highest profile game up to that point and Sakurai clearly enjoyed the game a lot. Nintendo and SEGA helping to publish 2 did a lot too. Joker was not just a "Sakurai pick" either - unique gameplay mechanics, critical darling and ATLUS' peak up to that point.
So I strongly doubt someone like Arle, Reimu or 2B would be forcing it. They would be added not just because of Sakurai's taste, but also because they add something else to the Smash table. Gameplay stuff, their own flair and implied variety. Just like WFT and Little Mac.
Overwatch's Tracer would likewise be (partly) added for gameplay mechanics and her being the face of that game. Partly, those two would not be all of the reasons.
In fact, I remember you talking about MOBAs? One of these days, I had a fun conversation with someone else here about the possibility of a rep from League or Dota 2.
Hey, thanks for remembering that convo! Speaking off "What the F***" picks (since we seem to be the only (edit: three) here familiar with MOBAs). I'll reiterate: I've been bullish on a rep from that genre. Of course, we don't know if Sakurai likes that genre at all, but I'm pretty sure he knows of it.
Why am I sure he knows of it? Not just because he looks far and wide, but also because of Nintendo's Chinese partner Tencent. I'm pretty sure Tencent would've considered their only big option internationally (LoL) and maybe even suggested that for negotiation. Negotiation doesn't mean that it's going anywhere, but we'll see if Riot's Fighting game makes its way to the Switch. Dota 2 does have the OG factor and Valve's backing, but they're also reliant on a spin off game getting to the Switch.
I'm leaning towards LoL if only because Tencent's practically hugging Nintendo, but I would not count out Dota 2 because of the OG factor. And yeah, I'm still standing behind Ahri, Ryze and as you said when we discussed, Lux as the three primary LoL picks.
Both Nintendo and Tencent being pretty close to SNK helps lead me to this assumption.