Cervical stenosis means that the cervix is stiff and unstretchy. This is due to the scar tissue post-surgery. The cervix is normally rather soft and opens for ovulation so that sperm can get in, and it opens again for your period to get out. And it dilates 10 cm for a baby to be born!
Any time you heal, you may have scar tissue. For some of us, we don't scar very badly after wounds, but some people develop big scars, and the same is true inside of us. If you tend to have big scars on your skin after you get cut, you probably will have more scar tissue after a cervical surgery, too. Multiple injuries to the same location also result in more scar tissue.
If you have regular periods, even if you have cramps, after surgery, your cervix opens enough for sperm to get through. If you don't have periods, then the cervix is too tightly closed, and sperm can't get in. This is rare, fortunately. If it happens to you, doctors can try to stretch open the cervix through the vagina.
If that doesn't work, then they have to do another surgery to open it up. That's a little more complicated, but also rare.
Scarring that results in a tighter, stiffer cervix is very likely to happen to you to some degree, but it's not something that is typically a real problem for getting pregnant. You won't even feel the stiffness, although it may make your periods a bit more crampy.
For some women, though, it is a problem that makes getting pregnant difficult because the stenosis is so severe that it distorts the cervix. Normally, your cervix is a pretty short, straight canal, but scar tissue can make it too tight and even crooked. If you have been trying for a while, and nothing else is wrong besides stenosis, you might look into pelvic massage to loosen the scar tissue. There is a place called Clear Passage that specializes in this. Or you can talk with a reproductive endocrinologist (fertility doctor) about procedures like intrauterine insemination that can bypass the cervix with a catheter.
While it doesn't usually impact conception, it can prolong labor and delivery by slowing down dilation and that can increase pain. It happened to me (go to my labor), but I did fully dilate eventually with some help.