This one is all but confirmed but here it goes. MSC recently released a press release (which has since been redacted) when their latest ship to enter drydock for the Renaissance stretching program. Contained in there, and saved by CruiseIndustryNews, was this quote:

…once the Renaissance Program is completed and the last of seven planned ships is delivered.

MSC only has 4 confirmed newbuilds on the books. The 2 in Fincantieri and the 2 at STX France. This can only mean that options were picked up. This leads to one additional ship at Fincantieri and two more from STX France.