Nah the actual in universe explanation is that Dobby is weird for wanting to be freed. Literal direct quote from Goblet of Fire

“But Harry set Dobby free, and he was over the moon about it!” said Hermione. “And we heard he’s asking for wages now!”

“Yeah, well, yeh get weirdos in every breed. I’m not sayin’ there isn’t the odd elf who’d take freedom, but yeh’ll never persuade most of ’em ter do it — no, nothin’ doin’, Hermione.”

Hermione looked very cross indeed and stuffed her box of badges back into her cloak pocket.

Still no, it's still a fictional story, just because you write a slave character doesn't mean you're pro slavery, just because you write a misogynist doesn't make you a misogynist, etc.

Again, she still might be, but citing Dobby as your evidence is stupid.