Ads on Twitch should follow Twitch rules
Ads that violate Twitch's Community Guidelines or focus on content that, were it a streamer's content, would violate Community Guidelines (such as prohibitions on implied nudity) should not be played on Twitch. Ads whose content, if streamed by a streamer, would require content labels, should only be played on streams with those content labels. A streamer who takes care to ensure their stream is family friendly should be able to stream knowing that their viewers will not be subject to ads featuring implied nudity or a shot zoomed in on bikini bottom-clad buttocks.
And yes, the Sydney Sweeney ad inspired this idea, but this request is not about the controversy surrounding the ad or Sydney Sweeney, it is about the content of any ad that plays on Twitch: Ads should be subject to the same rules as streams.
If Twitch doesn't vet ads by the same rules, then there should be a feature that enables viewers to report ads for violations of Twitch Community Guidelines.