I keep being told othereise, that the redulting "neo-vagina" isn't 'proper' vagina. This site is the only one that gave me a definitive explanation but I would like too see if there are more.
It's true that the microbiome and microscopic structure of the neovagina are not the same as those of a natal vagina, although explicating this outside of circumstances relating to post-surgical dysfunction or pathology seems unnecessary and a potential source of discrimination. Whether post-surgical outcomes are "proper," as you put it, should be evaluated on the basis of patient satisfaction and nothing else, especially not appraisals of minute features.
Microbiology of the neovagina
When assessing a troublesome discharge or bleeding from a neovagina, it is important to keep in mind that the histology and microflora of the neovagina is different from that found in the natal vagina, and hence the aetiology of vaginal discharge in trans women is different from that of cis women. Premenopausal cis women have a vaginal epithelium constructed of glycogen-rich epithelial cells that support the growth of lactobacilli, these produce lactic acid to maintain an acidic vaginal pH and so help to curb the growth of other commensal bacteria. When this mechanism fails, the resultant bacterial vaginosis is characterised by an overgrowth of Gardnerella vaginalis and other anaerobic vaginal bacteria. Neovaginas are not lined by a glycogen-rich epithelium. The microbiology of neovaginas created by penile infibulation and those created by intestinal grafts are discussed separately below.
These more in-depth discussions of the various microbiomes imparted by different approaches to constructing a neovagina begin on the third page (444) of the linked PDF.