The data of the Etruscans' mtdna are clear. Only those who are biased do not accept them.
Compared to Parma Beaker like, most modern Northern Italians have more CHG.
Compared to Tuscans, all the central Italians (Marche, Umbria, Lazio) and southern Italians have more CHG than Tuscans, including the Italic and Greek areas. The difference in CHG between Tuscans and many Ligurians and Emilians are small. Romagnolis seem more similar to Adriatic people from Marche.
So it is quite clear that the extra input of CHG in Italians is not due to the Etruscans, and anyone who is impartial has already understood this a long time ago.
The Romanization of Italy increased CHG here and there in Italy. It was likely not (always) a Nordicisation of the Italians as had always been believed. Latins, after all, were very few and they couldn't have completely changed the genetics of the Italians. But it's quite clear that Romans were Latins mixed with something else, and what shifted the Romans further south could not be due to the Etruscans.