I agree with the above, but also have to comment, that if he's on interferon, he may be not be quite the same partner. My partner was bereft of my physical company for the majority of the course of interferon. Of course, that was just me, and I loved him no less, but wasn't up to being too physical.
What you have read is correct. It's related to pregnancy. You wouldn't want to become pregnant while your husband was on treatment. It doesn't sound like this is an issue. Since you won't be getting pregnant.
Best to You
No, you do not need to use contraception if you have had a hysterectomy. Ribavirin can cause major birth defects in a fetus and that is the reason for the contraception but, since you have had a hysterectomy, there is no way you can get pregnant and, therefore, there would be no need for using contraception when the two of you have sexual relations.
Best of luck to your partner in his treatment. And best of luck to both of you going forward.