A post-op transwoman can definitely have normal vaginal epithelium, depending on the technique used. For example, split thickness skin grafts are known to facilitate this in transsexual women, intersexed persons and normal women with no vagina.
Here is an example of how split skin grafts can undergo metaplasia
due to the local environment and become normal vaginal mucosa.
Eur J Obstet Gynecol Reprod Biol. 2005 Jul 1;121(1):110-6.
Treatment of vaginal agenesis with modified Abbé-McIndoe technique: long-term follow-up in 22 patients.
Keser A1, Bozkurt N, Taner OF, Sensöz O.