I don't think you are. The whole point of airgapped cold storage is to be as secure as possible, right? You trade off the convenience of being able to send coins in seconds from a mobile wallet or a hot wallet for the added security of keeping your private keys permanently offline. Well, this security applies to both sending and receiving, I think. Just as you obviously have to use your airgapped wallet and not just your watch only wallet when sending coins, I think it is good practice to also check with your airgapped wallet when receiving coins. I'm not interacting with my cold storage on a daily basis like I am with my hot wallets, and so the added two minutes to boot it up and double check the address is a small price to pay for the added peace of mind.

If you really can't be bothered to boot it up every time, then I suppose you could boot it up and write down the next 5 or so receiving addresses on paper and keep them somewhere safe. Then, when you want to generate a new address from your watch only wallet, you can immediately check against your piece of paper that the address is correct. Only risk here is compromising your privacy if someone finds your piece of paper.