I may be reading different posts to you, but the two main regrets that I feel coming across from TS folk like myself are:
1 I regret hiding from my true self for so long
2 I regret the trolls who try to disrupt the discussions by making outlandish and disprovable claims about all CDs being closet TS
I don't see much evidence of TS folk reverting to their previous gender identity and becoming cross-dressers again, but neither do I see much evidence of cross-dressing leading to becoming transsexual (although someone who is deep in denial may rediscover themself through cross-dressing).