hysterectomy can cause prolapse. in fact prolapse is actually more likely after hysterectomy.
there are lots of sorts or prolapse.
womb dropping down,
bladder pushing into vag,
bowel pushing into vag,
vag pushing out,
etc.
i believe there's a 'vault' prolapse caused by surgeons failing to tether the end of the vag properly inside the body once it's no longer held onto the womb.
and sometimes the squeezy muscles on the outside can be strong but the wall of the vagina and/or the tissue holding it in place are damaged.
there are so many damn variations on prolapse that i forget... it's been a long time since i researched thoroughly and i cannot be arsed to do it again.
The vagina would fall completely inside out of the opening if it weren't tethered to something. Just loose tethering causes what you are seeing in these videos. Having seen many hysterectomies, those from vaginal to abdominal, partial to total...and none of them have forgotten to put the vagina back where it is supposed to be by suturing it to the pelvic ligaments. If they didn't it would be very obvious before she even woke up from surgery.
They also do a couple of tests to make sure everything is put in it's proper place by tugging and pulling.
Now a variation on what is considered too tight, just tight enough or not tight enough is what is the issue. A lot of women before getting a hysterectomy had a problematic prolapse interfering with their ability to hold urine, release urine or defecate. It can have very negative consequences to a woman's daily life.
How this sutures hold up, the laxity of the tissues to begin with and what stresses might be put on them is a whole different issue here.
There is a fetish of suctioning the cervix to the point where you can pull on it over the course of time in order to see it at the vaginal opening. This is stretching of the pelvic ligaments that allow for this to happen. What they don't realize is that these ligaments can't be tightened back up without surgery.
Do I think the women in the videos listed are in pain or having other problems that need to be fixed? Not necessarily. I'd say if they don't even notice it and aren't having other symptoms that indicate things are out of place and causing problems, then leave things where they are and avoid a painful surgery until you need one unless your daily functions are being affected negatively.