Except they only banned him after the insurrection. Not before.
The hashtag alone has been used within and without the context. Twitter has tried to ban certain hashtags before with little to no success. So most tweets and accounts that are scrutinized need more context to result in a disciplinary action.
His tweets, which they allowed him to post and promote his conspiracy of election fraud despite many reliable sources saying otherwise were given warnings as the sole disciplinary action instead of what would’ve happened if he was a regular civilian. Many Twitter users (both liberal and conservative) posted tweets that were word for word what Trump wrote and were banned! Yet Trump was allowed to continue. This is why the warnings were placed on his tweets in the first place.
It is potentially illegal to edit or remove the words of the President so he was given exceptions. But they are allowed to ban him for abusing this exception to continue to break their terms of service by posting tweets that broke their terms of services for other users.
When the attack on the Capitol happened, Twitter decided to ultimately ban Trump and prevent him from continuing to use their platform which may have been a contributing factor to the attack.
Initially, the ban was only suppose to be for a week, but Trump tried to create alt accounts, much as an angry child would, so the ban was extended to a permanent one as a result.
No, not everyone is going to get banned for using a dubious hashtag. But high profile accounts that continue to break their tos may ( and should be) scrutinized harder than the few accounts that slip through Twitters moderation.
I would not call it explicitly hypocrisy.