What does Oh Brother... reward?

Oh Brother... gives a choice of Miner's Revenge, Miner's Workgloves, Miner's Workboots, 1,550 experience.

Where does Oh Brother... start?

Wilder Thistlenettle in Stormwind City offers it.

Its level has not been recorded yet; it shows once a player accepts it with the addon running.

No. The quest exists in Classic Era as well.

World of Warcraft: Forever · quest

A quest in World of Warcraft: Forever, offered by Wilder Thistlenettle in Stormwind City. Recorded by 4 players running the addon.

Level and objectives show once a player with the addon accepts the quest.

Item	Given	Item level	Vendor sell
Miner's Revenge	as a choice	20	17s 75c
Miner's Workgloves	as a choice	20	2s 75c
Miner's Workboots	as a choice	20	5s 47c

What does Oh Brother... reward?: Oh Brother... gives a choice of Miner's Revenge, Miner's Workgloves, Miner's Workboots, 1,550 experience.
Where does Oh Brother... start?: Wilder Thistlenettle in Stormwind City offers it.
What level is Oh Brother...?: Its level has not been recorded yet; it shows once a player accepts it with the addon running.
Is Oh Brother... new in WoW Forever?: No. The quest exists in Classic Era as well.

Source: what players running the addon saw in the quest windows; the quest text itself stays in the game. Every quest seen · Stormwind City