I read the same article and found the title misleading. It starts by saying it is "worrying" but then when you read the article it goes on to say:
"That doesn’t mean the new GPU will necessarily be slower than the 6800 XT. In the tests for our
Radeon RX 7800 XT review,
we found the new GPU was still faster than the 6800 XT, despite having fewer compute units, thanks to the improvements made with the new RDNA 3 architecture, for example."
So if the same holds true for RDNA 4 then it is a pointless article.