Can warriors use mail transmog 2018

According to the official World of Warcraft Transmogrification Guide, Warriors can indeed use Mail armor pieces for transmogrification.

In the 2018 patch notes, there was no specific mention of restricting Mail armor for Warriors, and the general rule is that any armor piece that can be worn by a Warrior can be used for transmogrification.

So, to answer your question: Yes, Warriors can use Mail transmog in 2018 and later expansions.

Keep in mind that some specific armor pieces might have restrictions or limitations, but Mail armor is generally available for Warriors to use for transmogrification purposes.