If your Marketo Sync User cannot properly see SFDC COntacts and Accounts, then it won't sync.
I'm pretty sure they will sync over once you adjust your permissions. I am unsure if the specific advice they gave is correct. But it is the default advice if you check docs.marketo.com for how to implement Marketo the first time.
My understanding is the SFDC Contacts should sync over immediately. Perhaps Support wants you to force a sysmodtimestamp so Marketo knows what to do.
Thanks Josh! I don't know how else to adjust my permissions outside of the Mkto Sync user Profile and under "Object Settings."
I had provided access to read,edit,and view, when I edited the contact under those permissions it wouldn't sync, but as soon as I checked of "Modify All" and "Edit All" any edit made on the contact would then sync - over.
Is there another permissions area I could be missing?