A weakness in the way these guidelines are worded is that it's not clear enough how much security experts discourage people from using email. Email is the single largest risk most at-risk people have, and not just because only 2 email providers have a team capable of securing their infrastructure or because the protocol is weak, but also because of existing collection capabilities and because of its "archive-by-default" design.
Yes: if you are using email at all, you should use Google's email service. Virtually every concern you'll state about using Google Mail is better articulated as a concern about using email at all (especially because 90% of the people lawyers and activists communicate with also use Google Mail).
If you want, instead, to militate against using email at all, I'll agree and also tell you that I expect this guide will get clearer about that.
Why g-mail instead of a more security focused provider like proton-mail? It seems to me like the only downside of proton-mail is that it is less well-known, but I'd compare it to signal vs whatsapp. And you can get journalists to use signal.
Only other thing I can think of is google being more secure by virtue of being bigger.
Yes: if you are using email at all, you should use Google's email service. Virtually every concern you'll state about using Google Mail is better articulated as a concern about using email at all (especially because 90% of the people lawyers and activists communicate with also use Google Mail).
If you want, instead, to militate against using email at all, I'll agree and also tell you that I expect this guide will get clearer about that.