Is volume expansion possible upon dissolution of solute? I am aware that there is volume reduction upon dissolution of ionic solutes, due to the formation of hydrated spheres of aqueous ions where water molecules aggregate around the solute ions.

But similarly could there be a volume expansion?
Yes. In thermodynamic jargon, the onset of a change in volume under dissolution is known as an excess volume. If the solution takes up less volume than its constituent parts it is said to have a negative excess volume. Otherwise we have a positive excess volume. You might also find the term excess molar volume.
By googling each term we find many results concerning this, which seems to mainly manifest in metal alloys.