What part of the deck is he planning on using the Western Red Cedar for?

To the best of my understanding, all of the deck: flooring, handrails, pergola, lattice, etc.

My main question was the deck framing not being built from WRC as it is a soft wood and not strong enough for substructure. No issues at all from my end on using it for any of the above as a matter of fact it is very often used as your describing it.

Be aware that WRC will turn grey within a year.

Thank you very much millworkman. I am going to query the contractor to find out what they will use for the deck framing as that was not listed in the estimate. I don't know if he plans on using the current framing or not, but will find out.

Ntruro, I don't mind the grey at all, but thanks for the insite.

Just got the info that the deck graming will be treated ground contact pine. Does that sound like it will be okay?

Sorry, the word should have been framing not graming. Is treated ground contact pine a good choice for the framing?

Some Cabot stain will arrest, or help that graying.
Be aware, WRC is soft compared to other woods, so moving furniture, walking in heels are considerations.

Treated Ground Contact Pine would be the correct choice for the framing.