If Trump is banned from Twatter, they will lose over 60 million users. Advertisers will walk away and the Twat will be no more.
Question will be whether there is enough time for Trump to do any damage to social media with the election 6 months out?
Not with this Executive Order, no. It's dependent on other Federal Agencies to act and they may or may not. And if they do then the lawsuits will kick in. Real impact to social media is a good year away at best.
I think the way Trump could REALLY screw Twitter is to just post links on Twitter taking folks to his posts on Parler and Gab!