This "report" is beyond sketchy and isn't worth repeating. The source is a Korean blogger who just reads supply chain rumors posted on Chinese social media.

Do you know what kind of products supply chain sources can't leak anything about? New chips that are, by more credible reports, still 2+ years away from release at the earliest. The supply chain doesn't know anything about Apple's progress on chips until it's actually close to time to start manufacturing them. The only sources who can know the current status of Apple's modem developments are internal ones working in their never-leaked-anything chip development labs. The supply chain will learn about it when Apple needs to start preparing for manufacturing.