I think you either heard them wrong, or misinterpreted what they said. I paid special attention to that part, because they answered three of the questions I asked on the forums.
The answer to my question about whether they’ll be changing how you obtain Exiled Lands recipes on Siptah was that there are no plans to do so, because they want to keep the maps different, and that the inter-server character transfer will allow you to go between the two maps for the “unlocks” (this is the specific word they used).
The answer to my question about the grey-flower lupin, obsidian, sand beast bile glands, and Potion of Bestial Memory recipe was that the resources (lupin, obsidian, and glands) will be made available on the new land mass, but the recipe won’t, because the potion itself drops randomly from elite (alpha) mobs.
To hear the questions and the answers, go to the timestamp 01:01:51 in the recording of the stream.
All in all, the idea seems to be that they want the maps to be different in terms of how you get recipes, but the character transfer system would allow you to sidestep those differences if you want to.
Unfortunately, that doesn’t give us any clarity on whether they’ll allow item transfer or just feats.