Official press release says modems for Smartphones are cancelled and the rest are under review. Since many APs use integrated LTE modems that points the reason squarely at Apple.
Charlie says the entire modem project was cancelled several months ago, presumably because they knew they couldn't meet Apple's deadline, and without Apple they can't justify the development expense. The "under review" is of course just PR so people don't start asking questions about why they couldn't; especially if the answer is basically 10 nm one way or another.