Well, it should not come as a surprise really, SLi and Crossfire are going the way of the dodo. Even with the recent launch, you will have noticed that the Radeon RX 5700 and RX 5700 XT have no support for multiple GPUs by CrossFire.
CEO of AMD, Dr. Lisa Su, was asked about Crossfire this over at the Hot Chips press conference. She said: "To be honest, the software is going faster than the hardware, I would say that CrossFire isn't a significant focus"
The older and current RTX cards and Turing series from competitor Nvidia still support SLI / NVLink. Albeit NVIDIA also is stepping down on multi-GPU gaming.
Crossfire is no longer a significant focus says AMD CEO Lisa Su