Plivez
Not exactly, I don't know the area immediately around Metz well having only travelled through it on the way to somewhere else.
I don't think the immediate area around Metz is that great but go a little way south and I can vouch for the countryside in the area around Nancy being quite pleasant and also to the north Around Trier in Germany.
My usual ploy when sorting out rides in France is to go to the Michelin Map site
HERE and look for the roads edged in green. These are the scenic roads and usually more interesting for riding if you know what I mean
Why Metz? There are much better biking areas such as the Ardennes to the north of Charleville Les Mesieurs
Skiddy