So the AMD 6000 family will be the last graphic card family the hack world will get?
We don't know.
We don't know.
All we have is speculation. Anyone who knows Apple's decisions on this will be bound by NDA. They might be working on it right now. They might have already decided not to support it. We did get that one recent positive sign: the quote from the Octane X developer who said full support would come with the release of 11.3. But he also said that 11.3 beta 3 already has support, which it doesn't, and we don't know what the basis for his statement was; whether it was based on communication he'd had from Apple (in which case he probably wasn't meant to say it in public), or if he was just quoting hearsay and getting it wrong.
We'll just have to keep waiting for each new release and hope for the best.
My personal speculation has always been that the 6000-series will be supported - to allow current Intel Mac users to use them for the next 18 months until Apple Silicon is available in all configurations and the Apple GPUs are competitive. It always seemed too early in the transition for the latest (and best performing in years) AMD GPUs not to be supported.
Though it's also possible to argue that Apple may well not want high-performing third-party GPUs around just as they're trying to push people to upgrade to Silicon. Locking existing Intel Mac users to last-gen AMD GPUs would arguably help 'encourage' them to buy a new Silicon system. So it's never been a sure thing that support will come.
Even if support does come, I further speculate that it's quite likely that no further third-party GPUs will be supported beyond that. The Apple M1 systems have Apple-built GPUs, and no support for external GPUs, which seems likely to set the pattern for future Silicon machines. And all the rumours coming out indicate they plan to scale up those GPUs significantly, likely into the realm where they would compete with - or beat - AMD and NVidia's top offerings. Recent rumours talk about future 64-core and 128-core GPUs; the AMD 6900XT has 80 Compute Units, for comparison.
As I say, it's all speculation. But Apple is the richest company in the world; if they want to do something, they can. And they've always loved locking consumers into buying only Apple products and upgrades.