This old issue still bugs me a bit. I have gone as far as switching to the main move 2.d3 d5 just in case White is planning some 2.d3 c5 3.g3 trickery! But it would be nice to have 2.d3 c5 as an option.
Has anyone seen Marin's recent French databases for Modern Chess? I haven't bought them yet, but I have a lot of respect for Marin and some hope he thought of addressing this.
I've had a good look at
French Defense: The Solid Rubinstein Variation by Hannes Langrock, and it has the same problem as Williams' repertoire book: Recommends 2.d3 c5 (in Langrock's case following up with 3.Nf3 b6 and an interesting and fresh Hedgehog setup), but pretends that 3.Nf3 is the only possible answer! No mention of White alternatives on move 3, like 3.g3 or 3.f4, as far as I can see.
What's perplexing is after Chigorin's 2.Qe2 c5 Langrock is perfectly happy to consider a range of White tries: 3.Nf3 Nc6 4.g3, 3.Nf3 Nc6 4.c3, 3.f4 and 3.g3. So after 2.Qe2 c5 White has lots of options, while after 2.d3 c5, 3.Nf3 is somehow forced?? It just doesn't add up.
Otherwise Langrock's book looks excellent btw., so I'm not condemning the entire effort based on this small oversight. It even covers the French Advance line OldGrizzly asked about in great detail. But I think I will contact some of these authors and ask them to fill this 2.d3 c5 3.g3/3.others gap.
I also checked Rogozenko's old Anti-Sicilians book. He very sensibly meets the Big Clamp with a Botvinnik system with 1.e4 c5 2.d3 Nc6 3.g3 g6 4.Bg2 Bg7 5.f4 d6 6.Nf3 e5 (wih 6...Nf6 as a backup line), which means his coverage is not useful for a French player.