Hi! https://puppet.com/docs/puppet/7/core_facts.html mentions a few facts that are listed as legacy for some time. I think puppet 8 (or facter 5?) would be a good time to drop them. The structured facts provide alternatives and the reduced amount of facts would be helpful to reduce the data sent to puppetdb. Do you already have a timeline here?
bastelfreak we tried switching puppet builtin providers to using structured facts, but that introduced problems within the puppet ecosystem. I've linked this ticket to the other one. I agree we'd need to do this in puppet 8 as modules would need to be updated to stub the appropriate set of facts for provider suitability/confining logic.