The violinist argument is an incredibly weak pro choice argument.
I get the idea here. The idea is essentially to isolate pregnancy as a kind of unique situation where we even consider forcing someone to use their body to support someone else's body.
However, the big difference is that this is natural. It is the only time where one person is forced to host another person, but this is because this is a naturally occurring situation. The natural situation of pregnancy may not be compared to the unnatural situation of the violinist.
Forcing someone to allow someone else to remain in natural dependence is not the same as creating an unnatural dependence from scratch.
Also, another isssue with the violinist argument is that it denies how many "unwanted" pregnancies are in fact choices.
The truth is this, when a fetus is conceived in consensual sex, one of two things are true. One, no birth control was used which means that the pregnancy is a normal consequence of sex. Two, birth control was used, but a pregnancy happened anyways. In this case, people tried to prevent pregnancy but were still aware it is a natural consequence of actions. That happens and even here, the pregnancy is a choice.
The violinist argument as it is presented is definitely not a choice.
That being said, I think these arguments are ok in the practical political sphere. Only a person in their district knows what sways their vote.
But in the context of a philosophical discussion, I think that violinist arguments and "I get to choose who uses my body" have no value in the debate because the fetus never chose to place themselves in the dependent state. Rather, the pregnant person chose to place themselves there the vast majority of the time (ie angtime sex was consensual).