So... that spiderman shirt... (new job tease)

[Powercow]

So again, can you please show me how and where it was mentioned in the lore?

The one comment about Doomtrain from that event was from a single NPC making a comment about misplacing his Doomtrain minion. Not the same thing as the director saying "yeah, these two jobs would be nice for the expansion" and having one of them be confirmed.

For in-game lore, the current Legatus we've been going against this entire expansion uses a katana and fights in a similar style to previous FF Samurai (think Jack, X-2, and XI.)

The MCH guild was not in the game until 3.0. What you're thinking of is the cut MSK guild, which isn't the same thing.

Furthermore, if you're going to say "oh the Ishgardian astrology tower was CLEARLY a prelude to the wildly different Sharlayan-style astrologians we become in 3.0" then I'm sorry to say but you're reaching really, reeeeeeeally hard there. You could point to any part of the map and claim that's foreshadowing for future jobs -- Merchant! Dancer! Shepherd (this one DID have a guild in 1.0 too!) Necromancer! Demonologist!

Edit - Oh, and Red Mages have effectively no in-game lore right now either. But I have faith the dev team will take the NIN approach and add some for them leading up to it, or they'll take the MCH approach and have it come out of nowhere and fit perfectly.