WhatsApp calls and other functionality based on push messaging work fine on GrapheneOS. You're describing an issue created by how he set up his device rather than any missing functionality on GrapheneOS. There are multiple ways apps can handle push messaging and all work fine.

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MicroStrategy founder Michael Saylor asserts that Bitcoin has won the global narrative war, specifically naming BIP- […]
The article, "Michael Saylor Warns BIP-110 is the Biggest Threat to Bitcoin; Four-Year Cycle is Dead, Institutional Capital is the Real Protagonist," was first published on BlockTempo, the most influential blockchain ABMedia media.

Michael Saylor warns that BIP-110 is the biggest threat to Bitcoin; the four-year cycle is dead, and institutional capital is the real protagonist.

Bitcoin at Block – the Bitcoin project of Block , the company founded by Twitter co-founder Jack Dorsey – has just announced the launch of a free Bitcoin Faucet, marking the return of the Bitcoin distribution model...

Jack Dorsey announces a $1 million project to give away free Bitcoin.

Cryptocurrency has not failed; it has simply been targeting the wrong users over the past decade.