Should i keep em 19 or not worthy?
Definitely keep. Even if you didn't update them, why level them? Just leave them there and level something new from 1.
Well, one thing to point out as is that unless WoW Armory is messing up and incorrectly scaling-- many of your enchants are INSANE and no longer available to the 19 bracket, so that may affect the BiS standing of them. Your leg armor for example is giving you a whopping FIFTEEN agility even after being scaled down from its max of +19. Same with your +5 Vers rings which are pretty much universally +1 for everyone else. My advice would be not to get rid of a single piece.
WoW Armory is messed up and is incorrectly displaying unscaled enchants for chars that haven't logged in since the stat squish.
Willy the rogue has the full blackened defias set, which is cool AF and not obtainable anymore. Not usually BiS though. Argas is now grandfathered at ilvl 32 and is BiS or tied for it. AGM is no longer obtainable. Shadowfangs are still obtainable, though expensive as fuck. Shadowfang is BiS offhand, and still really good mainhand. You might have other pieces in the bank.
Willy the shaman has talbar mantle, maybe inferno robe?, double argas, and AGM which are all GFd.
Ytny the other rogue has tunic of westfall, argas, and AGM. Also the belt may be grandfathered at that ilvl, though it isn't amazing. Just 1 more possible secondary than the new ilvl 23 version.
The mage has talbar, inferno robe, GFd ilvl 25 belt, argas, AGM.
All in all, you got some sweet gear. Just need a few updates. Theres a guide in my sig for gearing new twinks, you'll want to play around with that gear and fitting some of your GFd gear in where possible. Don't throw any of your old gear away. Check your bank for other gear. Anything ilvl 24+ is probably GFd. Feel free to ask if you don't know if something is GFd or if you want to know if a GFd item is BiS.