I mean I guess Divinity never had ads unless you consider the launcher an advert for their other titles, given that that's basically what it's there to do?
If you don't consider anything in launchers to be adverts then I guess you can play BG3, because that's where the advert for the DLC lives?
I really feel like if Larian had only given you the soundtrack and not the cosmetics, and just not called it DLC, that people really wouldn't be so up in arms about it.