There is no any social media coin that I know of. The social media that want to have a coin like Libra for Facebook did not become a reality.
Is Reddit want to have any coin? I do not think so.
Yes Reddit managed coins but coins created specifically for their subreddits These are Moon and Bricks
MOON is a community token created for the r/CryptoCurrency subreddit. Tokens are given as rewards for users’ comments and posts
Brick is a community token created for the namesake battle royale game’s subreddit r/FortNiteBR
Since 2021, Reddit has been launching its cryptocurrencies as part of the Reddit Community Points initiative to incentivize content production. When users exchange their community tokens for rewards, Reddit will cover the gas fee needed for the transaction. In addition, tokenholders can participate in governance proposals that introduce new functionality to the tokens.
.
https://cointelegraph.com/news/reddit-community-tokens-soar-kraken-listingWe never know in the future if they will launch their own governed coin for the whole community, The two tokens are doing great, so there's a possibility that they create another one and make it a form of incentive for their content creators on the whole community.