Yes, I'd say that there is generally an element of things going your way when your prospective opponent from decent ranked vs unranked turns out to be the unranked player. When lower ranked or unranked players make it through in your bracket it is generally to be welcomed though clearly you get "ringers" at times.

Your strongest possible opposition would very likely be that ranked player playing near his best, and you have avoided that. The unranked / lowly ranked player who has won one or two matches against the ranked player is as RJA says clearly playing reasonably well, ( just by the the simple result the better player this week in the orevious round(s) ), but is very unlikely to have as dangerous a top level. and is likely to be less consistent from match to match.

All the best to Alex. I recall folk who have seen him in the past saying he has quite a spirit about him. I had expected him to make it at least say into the top 1000 well before now. But I have no idea of what issues he has maybe faced.