Office 365 with Dirsync needs local exchange to manage?

I was just informed, that to successfully implement Dir Sync for office 365 and a local DC that I would still need an exchange server, not to transport traffic or anything. But to have the Exchange Management Console, because the Dir sync or ECP will overwrite the O365 changes?

Does this sound accurate ?

Any input is greatly appreciated.

Thanks,

Emilio M.