"The advertisers won't pay more just because the stars now get paid more."
false.
No, he is correct. The advertisers pay based on ratings. The network certainly isn't going to cut them a deal, they will charge the maximum they can, regardless of the production costs. It's the ad buyers, not the networks, in the driver's seat when it comes to price. Just because the actors get a raise doesn't mean that the ad rates are going to go up. Not to mention that most of those rates are probably done deals by now, well before this was even announced. With all the cable choices these days, network TV ratings are in the shitter. A show pulling a 4.0 in demo is a hit today, where 20 years ago it would have been cancelled on the spot. Advertisers have a huge choice of where to spend there money when it comes to media buys and they won't hesitate to use that leverage to keep prices down. CBS can't go to them and say "Look, production costs went up, so you need to pay more". They will say "Ratings didn't go up, so screw off. This is what we will pay. Take it or leave it."
WB is selling the show to CBS, and they are doing so at a prices that's probably near costs. Since WB owns the show, not CBS, WB will be the ones to syndicate it off network in the US, as well as first run and syndication rights in foreign markets worldwide. That is where almost all of their profit will come from. Studios can actually afford to lose money on first run for a show because they know they will make all of their profits in syndication. Sony Entertainment is famous for practically giving shows away so that they can get over the syndication threshold (generally around 80-100 episodes). 'Til Death and Rules of Engagement being two recent examples from them.
Now for the network, the profits are pretty much front-loaded. Salaries and other costs are lowest during the first 3 years, so if a show is a hit they stand to make bank with the understanding that their costs will increase over time (and, they hope, the show's ratings so they can increase their ad prices). Either way, they won't air a show they are losing money on. With how quickly this was resolved, I think it's safe to say that there is plenty of margin for them to absorb the increased costs at the current ad rate. TV shows are bait to draw in viewers (the product) so they can sell your eyeballs to advertisers (the customers). If the bait isn't working or it's not cost effective, they get rid of it and get something new.
So WB and CBS will probably share in the cost increase. In the long run it's a drop in the bucket compared to the show's profits, and it's not some unexpected cost, it's been planned for and expected. It definitely won't fall on the ad buyers unless the new salaries somehow ties into a ratings increase.
Now, if you have problems with how companies spend on ads then don't buy.... well, anything. And don't watch live TV. Or DVR recordings for at least 5 days so you are completely out of being counted in the C3 ratings that ad prices are based on. Vote with your dollar and eyeballs.