Motorola's flagships are going to be their first devices providing the updates and hardware-based security features required by GrapheneOS. It will come to lower end devices but it will take longer.

Snapdragon 8 Elite Gen 5 is the first Qualcomm SoC with hardware memory tagging (MTE). MTE isn't even available on the slightly lower end Snapdragon 8 Gen 5. A lot of the SoC security features are segmented based on price and only the flagship SoC platform has everything we need. Snapdragon's upcoming next generation SoC is the first truly providing everything we need. There's still a lot of work to do since providing the features on paper is different from having those fully integrated to match what we have on Pixels.