I believe I might be the only person since Els who visited both villages (at least among the reviewers). I visited Hahoe (Andong) in 2011, just after inscription and now I've completed the set with a visit to Yangdong (Gyeongju) in 2025. I will only cover the two villages, as the key associated Seowon (Oksan, Byeongsan) were inscribed again in 2019. Yangdong has been made modestly accessible to visitors (visitor center / museum), while maintaining its traditional character. Tourist trap, Yangdong is surely not. When you have infrequent buses in Korea, this will prevent the vast majority of city-dwellers from venturing out to the countryside. Therefore, I believe Yangdong specifically will not be overwhelmed by tourism in the foreseeable future. Moreover, the iconic sites of Gyeongju are nearby, which pre-occupies most domestic tourists.
Once you receive your ticket (WHS memento) at either village, you will be given a map. My advice (which is reflected in other reviews as well) is mark a couple key places as destinations to walk toward and then simply go explore. You might not see all of the best-preserved historic houses (if your time is restricted to 1-2 hours), but you will surely get a sense of the village and what makes it special.
Some of the best Yangban houses have been designated as treasures, making them ideal destinations within the village.