Automatically flag posts about currently airing shows as 'Potential spoiler' on the feed

Apologies if this or something similar has been suggested already, but I think automatically flagging posts about shows that are currently airing as potential spoilers is the only solution. This of course would only work if the show has been tagged in the post.

I often see warnings to avoid looking at the feed as a major spoiler has been been revealed. Users shouldn't be made to feel worried when scrolling the feed incase they accidentally stumble across an unmarked spoiler.