Depends how sweet your ice cream is, but my concern would be the ice cream melting. I like pavlova to sit for a little while, with the cream softening into the top of the meringue and making a fudgy texture. If you don't mind it not sitting then it would be fine, but I'd argue that it's not technically pavlova! Although - consider Baked Alaska - which is meringue and ice cream. That works!