Again, what would that look like if an actual political bias was in fact built into the algorithm? Certain keywords focused on what? Racial statements, religious statements, reproductive rights, what exactly would a programmer slip into an algorithm, be approved company wide, that specifically targets the tweets of one party and not the other party? Can it be done? Sure. Is it actually part of the algorithm? Very very unlikely.
What is more likely is, the algorithm seeks out violations of the terms of service (which are public) and flags them for review by humans, who make thousands of decisions on if the algorithm got it right, or the Tweet is in fact compliant with the ToS (or at least they used to refer to humans but I think they're all gone now)
What is also more likely, and fairly easily provable, especially now that Musk owns the code, is that one party Tweets in violation of the ToS more than the other party, making them think they are being treated unfairly. As the article you posted says, you don't even need to see the code, you just need to see the inputs and the outputs to know what the algorithm is flagging. The obvious result is, if you submit a lot of ToS violations you're going to get a lot of flags. That's not bias on the algorithm, its bias on the part of the person Tweeting.
Again, as Goon so thoroughly points out one post above, there are a jillion conservative posts every day on FB and Twitter. If the algorithm was truly biased against conservative messaging that would not happen. THe algorithm is in fact biased against violations of the ToS, as it should be.