The couple's romance storyline began when Sonya was introduced to the soap in late 2009, and viewers have since seen them overcome various obstacles together.
Moloney told The AAP of the pair's future: "I think they're well-matched. I think they'll be together for a while, although they're going to go through the ups and downs every relationship faces.
"The thing about these two is it's not a question of them loving each other, it's a matter of whether or not things go their way."
Discussing Toadie's romantic history, he continued: "I have no idea how or why but he's done okay, hasn't he? I think it's the thing of everyone wanting to see the underdog enjoy some kind of victory."
Toadie's current storyline on screen in Australia has seen him framed for a brutal attack on teen Chris Pappas (James Mason).
Moloney added: "He has to fight his way out of that one - with a bit of legal skill and a bit of sneakiness."
Neighbours returns to Channel 5 in the UK next week.
> Neighbours Toadie linked to shock finale attack
> Neighbours' Toadie to be framed for attack
> Read more Neighbours spoilers and news