I work near Melampo and eat there regularly and I'd noticed that Alessandro'd been gone since a little before the holidays but hadn't wanted to ask his young VERY FRIENDLY counterpart whether he was coming back or not.
Today the person in front of me in line asked and although I don't know why, apparently he's out of the sandwich business.
Anyone who loved the sandwiches there but feared Alessandro should head back. The sandwiches are as good as ever, plus the new guy (who'd been working in the back for a year or so) is making delicious fresh pesto almost every day.
He also has NO PROBLEM with substitutions.