Except that it straight up says so in the 10.1 PTR game files right now, on the Evoker only quest that says spec remembered that pops up on logging in.
https://cdn.discordapp.com/attachments/679773016703762440/1091450818185662495/image.png
From the quest https://www.wowhead.com/ptr/quest=72513/our-destiny on the PTR.
That was in the PTR files early last month, that was then continued with more recent content that continues along those lines specifically naming two NPC’s as the two existing specs, and Emberthal as another: https://www.wowhead.com/news/third-evoker-specialization-theory-supported-by-new-neltharion-voice-lines-332224
Tank as has been said is unlikely, but as to third spec, another poster said it perfectly: