Actually, 2010 uses an Outlook Anywhere endpoint, and you can migrate them directly from 2010 to ExO even if 2016 Hybrid is enabled.
So, in other words, what you want to do will work.
Migrate Mailboxes via the 2016 endpoint
Migrate the legacy 2010 Public Folders via the 2010 OutlookAnywhere endpoint.
Specfically:
On the legacy Exchange server, run the following command to synchronize mail-enabled public folders from your local Active Directory to Exchange Online.