I don't know about that, but I wouldn't be surprised...it would have helped them claim that the Moldovans were distinct from the Romanians. Both Romanian and Moldovan are mainly derived from Latin, but with many words acquired over the centuries from nearby languages. That part of the world has seen so many invasions over the millennia that probably every ethnic group is a mixture...so there could be DNA from Slavic ancestors among Moldovan-speaking Moldovans.
Actually, the Library of Congress Moldova, a country study states that eastern Moldavia and Bessarabia (i.e. modern Republic of Moldova) had Slavic influence from nearby Ukraine. Romanians in general have Slavic influence, but it's certainly possible, IMHO, that Moldavians have more than other Romanians.