Perhaps it can be compatible if you accept that volcels do not choose to be volcels. That is, somebody compelled to "choose" volceldom is in fact subject to a natural inclination or other precedent force compelling them to act as such.
Trying to think of examples, because of the vague definition of volcel:
One type of volcel might be a mentalcel who is physically attractive to women but too anxious or aloof to engage them. In such cases, one cannot choose to be mentally ill, and hence this scenario is compatible with hard determinism. In a sense they simultaneously have the opportunity to engage in sex, but, if they held back because of genuine mental fuckups, that's not really a choice.
What about a monk who is compelled out of faith to live a life of celibacy? Is it really a "choice," or a compulsion out of religious inspiration?
P.S. the definition of volcel is especially vague and indeterminate, and hence worthy of leniency in discussion. I mean, if I really wanted to I could go rape my mom or my dog right now? Volcel if you dont fuck your mom bro!