The ICOMOS document does mention: Notable among the urban settlements
are (from north-east to south-west) Sully, Orleans, Blois,
Amboise, Tours, Saumur, and Angers. - So that would be one point again in favour of inclusion.
There's a map of the nominated area on page 39 of the nomination dossier. Unfortunately it has no legend so we cannot see for sure what is within the core area. I suppose it's everything inside the red lines. So that would leave the city of Angers out, but possibly the Chateau in as it is close to the river.
On page 522 of the same document there is another map, from which could be concluded that the suburb of Angers bordering the river is in the border zone. The chateau isn't named as one of the core objects.
The German (!) Wikipedia also mentions that the historical center of Angers is included.
Ah! I always dreamed of being a detective...