While typical apps cannot access IMEIs, device serial numbers and other identifiers, they still know that I am using a Google Pixel. In most of the developing world Pixels are not available and extremely rare. No one you meet on the streets knows that Google makes phones.
This means that in practice journalists can be prosecuted for simply using a Pixel, as law enforcement can obtain logs that indicate a social media account was used in a Pixel. Instead of rigorously proving that it was indeed the journalist, they conclude that the journalist is the owner of the account since the target is "the only one in town known to be using a Pixel". Unfortunately in undemocratic jurisdictions such arguments do hold in court.
These situations could be avoided if the device model was spoofed to a more common one such as a Xiaomi, vivo or oppo. While simply spoofing the model name is defeated by thorough analysis, officials here usually lack the dedication and resources to do so. Does GrapheneOS have plans to implement such feature? Since Aurora Store provides spoofing I believe Graphene can also do it.