I needed to change the right tie rod because the boot was bad.
I removed the nut and I was getting ready to use the tierod separator (the U fork type).
When I put the fork in, the tierod just dropped out before I even used the mallet.
I was surprised, but didn't think much of it. I installed the new tierod and torqued to spec.

After the fact (next day), my mind was going through why the tie rod just dropped out that easily.
1) The nut came off without me using an allen wrench. which to me says the tierod had to be tight enough in the knuckle to keep the tierod from turning with the nut. The nut had nylon on it, so it was tight coming off the whole time. Not like the nut broke loose and I could spin it off the rest of the way.
2) I am wondering if the nut was not torqued properly 1-2 years ago and could have worn the hole in the knuckle so that the new tierod might not be fitting flush with the wedge shaped hole.
3) I looked at the OLD tie rod this morning and do not see any rings on the post, like you might see if it was loose and wiggling around.

So my question is:
1) How likely is the hole in the knuckle to get worn out (as in no longer wedge shaped, so the new tie rod will not fit FLUSH)
2) I am wondering if the knuckle hole could be worn slight hourglass shaped from the tierod being slightly loose, and the the tierod does not have the full contact it really needs.

There's no good way to gauge whether the taper in the hole is screwed up unless there's an obvious visible abnormality. Personally, I would never trust a knuckle that had a loose tie rod or ball joint stud kicking around in the hole for an unknown length of time. The mechanical loads on those parts are so high that there's almost bound to be some degree of damage, whether that's egging, warpage, or something else. If it was my ride, I'd replace it.

OK, changing a knuckle out is not a big job.
I looked at Rockauto...Do you trust Dorman brand?

I tend to go with Denso, Delphi, and AC-Delco. but they don't have any knuckles on RockAuto.

Dorman is a crapshoot, virtually all their stuff comes from China and you know how that is. The Chinese do fine when you hold them to proper QC standards, otherwise you get whatever makes them money. Maybe some other folks have experience with their knuckles, I haven't used them and can't speak to it.