question about bases

this site https://poe2db.tw/us/Staves#StavesItem
seems to show there are a bunch of staff bases
but i cant seem to find them in game.

are these confirmed to be legit? where is this site getting this info?

when will they be added?

i only ever seem to find the first few bases

Not in the game yet, if you want to check if an item from poedb2 is in the game use the trade website and search the item.
As for when? Nobody knows. Probably on release as they wont be releasing too much content just yet.