A "major evolution" would be for Apple to have informative two-way conversations with security researchers and to stop stiffing them for reports. I submitted a few macOS reports to the program, but Apple just sat on them forever, sometimes years, until I got frustrated enough to just publicly disclose the bugs. Needless to say, Apple never paid me a dime. For that reason, I don't actively look for macOS bugs anymore,…
Individual chains of course are still eligible for rewards:
> Individual chain components or multiple components that cannot be linked together will remain eligible for rewards, though these are proportionally smaller to match their relative impact.
Edit:
I think those that build a full chain and attempt to sell to the regular posse would rather just take the bug bounty from Apple. There's little information about the 0day market for chains but from what I've seen it is you need to provide long term support and hoard alternative methods when different parts get discovered or break down. With MIE and other mitigations and vigilant scanning of devices, there's more chance exploits and techniques are discovered, patched, and you as VR/ED will only get a small fraction of the contract (like say $8m over a couple of years). (Someone from the 0day industry feel free to correct me.)