Okey, for you that love tournament out there, you have to see this to prevent confusion...
If you don't know, Kevin Tewart is the Head Judge of Yu-Gi-Oh! TCG
Then what's about that post? It mean, the OCG Rule for Xyz SUmmoning didn't apply on TCG... The Xyz Material is treated as it IS on the field. So, when it is sent to the graveyard (either used for a cost of effect or the Xyz is destroyed/removed from field) the card effect of certain card STILL apply (Sangan and Goblin Zombie Still Search, Tengu still special summon), and it is treated as sent from the field to the graveyard (So, Plaguespreader still get removed if it special summoned by its own effect and used as Xyz material)
The rule completely Contradict the OCG official Rule about Xyz Summoning... Which stated Exceed Material monster no longer treated as being on the field (so, Sangan and Goblin Zombie isn't have their effect activated if detached, and so on)
And... Yes, the rule is already made official. Some Coverage from the newest YCS... A player already use it.
Regarding Priority... Although OCG has long lost the ability to declare priority to ignition effect, TCG haven't. Konami said, TCG still can use it until further announcement... But it is less likely to be announced since WCS is near and YCS is already started numerous time, but Konami still have no sign on giving explanation.
So, yes... Dark Armed Dragon, Judgment Dragon, and Chaos Sorcerer can still have some fun time on TCG.
Yes, now TCG and OCG have different Rule and almost like a different card game.