In one sense, it's trivial to prove, in that Twitter bans a lot of hate and abuse, and these days targeted hate is a popular tool of the right across the globe. (See, e.g., anti-gay and anti-trans panics going on all over. Or specific ethnic hate depending on region.) So if cracking down on that is being biased toward the left, then yes, Twitter definitely is.
But presumably you're saying something else?
In other words, conservatives do more stuff to run afoul of the terms of service, and they also receive better treatment. GP is wrong/misinformed.
https://www.techdirt.com/2022/04/18/fascinating-new-study-su...
https://www.theguardian.com/technology/2021/oct/22/twitter-a...
But even if you can substantiate "vanishing likes" as a problem, that doesn't prove much. Likes vanish all the time as Twitter rolls up bot networks. You'd first have to demonstrate that this was happening, and then show it was happening disproportionately to some accounts and not others.
And then once you had that, you'd have to show that the problem wasn't just excess fake engagement supporting right-wing narratives, as that's a very plausible explanation here.
The backlash isn't surprising; most civil rights advances end up with one. But the tenor of it is very concerning.
The Florida bill they are so terrified of would have never been drafted if public school employees never put gay porn in the library, people would have never got tired of Obergefell if not for the month-long religious festivals that lgbt movements like to hold so much. Lgbt movements create the conditions of their own societal rejection.
That right there is an insincere and obvious double standard. Let me know the minute that parents sue because a heterosexual teacher says they are married in a classroom. The problem is the gay teacher will be seen as other and potentially punished if they mention their spouse but the heterosexual teacher can speak out without repercussions.