People saying that in response to learning about a dog whistle is how you know it's a good dog whistle.

It's fully not, the head of marketing at the time actually has done multiple interviews about it.

"Subaru Lesbian" had become a meme in the queer community, and someone internal to Subaru found out that on self-reporting surveys of Subaru owners, Lesbians made up a surprising amount of the respondents

So Subaru decided to embrace it, with thinly-veiled advertising targeting lesbians

Yes and no. Subaru has a strong reputation in the queer community (or at least used to) because they were one of if not the first conpany to publically sponsor a queer sports player (female tennis player if memory serves correct but im sure somebody will correct me if im wrong). So even if not their intent, it's easy to see how it could be interpreted as such. They didn't earn the name "lesbaru" for nothing, they actually intentionally advertised to the queer community going back to the 90s if I'm not mistaken !

In one of them the license plate said Xena. It's a whole campaign originating from market research saying that lesbians were disproportionately likely to buy their cars