I can't think of any reason not to. He might get a bit stubborn and not want to eat without the canned, but don't cave! He won't starve himself
I don't know how often you take Gemma out but I live 25 Km. to the nearest town basicly I live in the boonies Anyway at least 2 or 3 times a week I have to go to town for some reason or another and I take Charlie with me. I always bring a little kibble with me just in case he gets hungry. My 3 older daughters and my grandkids all live in town so I go to town to see them as well. Its summer time now and I like to take the kids to the water park and spend the day with them and Charlie. I. Just don't want to have to cut my day with them short because I have to go home to feed Charlie his canned food and I don't want to have to carry ice around just to make sure the can food doesn't go bad in the hot car waiting for lunch time to roll around. Its easier to just bring a small bowl and some kibble and he can eat his lunch at the park.I did that with Gemma a few weeks ago. She was stubborn to eat at first but once she finally got hungry enough, she ate. She now gets water-moistened kibble three times a day, but I might just cut down to two soon with a few snacks mid-day because she rarely eats her lunch anyways.