I would suggest that mandatory cooking be discussed and agreed upon very early in the process, before just about everything, so that new members come in with an understanding that it is a given. I have visited a community where the mandatory cooking is resented. I believe the reason why is not that it is mandatory, but that their system is seriously flawed. Two people is not enough to make a happy cook team. It's so much work that you're exhausted after the meal, and dread cooking instead of looking forward to it.
Many communities seem to think that cooking is a necessary evil.
We have mandatory cooking, and it really is not a burden at all. We have mostly three person cook teams that stay together during a whole quarter at least, and sometimes stay together for years. That way people can find others whose schedules complement their own, and the chores can be divided equitably. Often, someone with time during the day will pair with others who don't mind doing the shopping or can do most of the clean-up. We don't have scheduled times when people can cook.