Not a chance of that IMO. Geography dictates that it's almost impossible without opening a third very active front and I doubt Ukraine have the manpower for that. Melitopol is protected by the very large and wide dammed Dnipro River
Before they get to Melitopol they'd have to also presumably skirt around Zaporizhzhia where the Nuclear Power Plant is
It's more important right now for Ukraine to take Kherson and all north of the Dnipro. Then they'll have the very difficult task of crossing the river, especially as they've blown the bridges out. Kherson Oblast is also a priority so they can control the canal from the reservoir, the canal that supplies fresh water to Crimea. The only fresh water Crimea gets. One of the first things Russia did on invasion was to undam the canal. For Ukraine its vital to prevent that water getting to Crimea.
Similarly once they can control south of the river near Kherson, they control one of the two entrances to Crimea. Once they can control that entrance they'll destroy the exit bridge to Russia, effectively trapping Crimea as an island unconnected to Russia.
All of that is far more important right now than Melitopol.