The Brief: "Tweets not loading" is a clapback on Twitter implying the author of a controversial tweet won't be able to withstand the backlash from their post, and will subsequently, either delete their account or make it private.

Bluesquiggle
DEEP DIVE

The phrase “tweets not loading” is a response to a controversial tweet, typically implying the original poster won’t be able to withstand the backlash from their tweet, and subsequently, will delete their account, change their privacy setting from public to private, block criticizers, and/or delete their original post. This then causes Twitter to display the error “Tweets aren’t loading right now.”