New Acquisition - migrating to O365

So you and Juan say to use AAD connect. I have Azure AD connect set up on my server since we just did the Hybrid migration to O365. Quick read looks like it does not need any special licensing to do this?  An outside vendor is the one that proposed to do the migration to a new tenant first.  They were going to help with some of this since I also have another acquisition at the same time.

We were having the acquired company set up a new 2016 AD server ( I don't think  exch 2010 will like that much) create a trust then join server to our domain, make it a DC with dhcp and dns. Migrate their users to this server using ADMT.  Again the vendor was doing this part and wanted us to have the email migration done already.  It does seem like a double migration so that prompted me to post on here. So would I leave out the ADMT and just use AAD connect?

Thanks