For a quick background, Apple doesn't allow the typical quarantine bypass of Gatekeeper for ARM64 binaries. It must be digitally signed to run. And Intel based Macs are a dead end with macOS Tahoe being the last OS released for them. So, brew is disabling the --no-quarantine switch in their next major release or so.

From the post: "What alternatives to the feature have been considered?

None. Macs with Apple silicon are the platform that will be supported in the future, and Apple is making it harder to bypass Gatekeeper as is."

While it is true that macOS requires binaries to have a digital signature, that can just be an ad-hoc signature. Other than that, not much has changed. Gatekeeper (and the ability to bypass it for specific apps/binaries) works much the same for unsigned Intel binaries as for ad-hoc signed Apple Silicon binaries.