Can you re-associate an Office 365 account to another AD Domain?

Greetings All,

We have a situation where we have a very poorly constructed AD domain and we are building a new domain (in parallel) to replace it.  We will migrate the users to the new domain and all the resources that we can.  The stumbling block is that the users on the old domain have already been associated to Office 365 accounts.  If we migrate the users to the new AD domain, will it break the connection to their O365 accounts, and if so can they be re-associated to the migrated account on the new AD domain?