It's more racist to cast your roles around fear of being stereotype adjacent and make your characters into the Greendale Human than it is to actually cast your show in a way that rubs up against stereotypes.
So it's not racist to make a group of black people to act like savages and kidnap a white woman over tribal rites so long as your characters are aliens. Got it.
So the "Dark on one side, white on the other!" episode from TOS wasn't a commentary on race issues of the era since, hey, these guys were aliens! The episode with the androgynous race in TNG wasn't about sexual orientation issues since the aliens on display were just that, aliens!
Get real. Trek has always dealt with topical issues by putting aliens on display who're having 20th century issues (that humanity had supposedly out-grown.) When you put on display a culture made up entirely of black people who act like savages it's pretty damn hard to NOT read into it something of a hidden message. Especially when it's known that per the director's orders all of the "aliens" had to black and the production decision to not give them so much as makeup squigglies or dots to make them "more alien" looking.
They were black people concerned over tribal issues who kidnapped a white woman and mad her perform in a savage game over marital/land rights. It's pretty damn offensive.
Why wasn't Worf in the episode? As state it's most likely because Worf wasn't much of a character in the first season which had a pretty heavy cast. This episode was also very Tasha-centric so there was little room to focus on anyone but her and other notable bridge crew members. It's also likely there's a bit of "plot convenience" here as it could be seen as things in the episode unlikely would have happened the way they did HAD Worf been around as his presence would have either been redundant to Yar's or negated her completely. (He would have been better at showing off the holodeck, fighting for example which is what piqued the interest of the aliens on Yar in the first place.)