Ah, I'd only heard about that aspect, as I don't watch the cartoons, didn't know it was considered canon, thought it was fan ficiton.
I don't watch the cartoons and don't know, how else am I to infer it, if you take the movie(s) at face value? So you're hit with Maul, and last time you saw him, he was tumbling down a shaft after being cut in half, and here he is talking to Qu'ira at the end of Solo. If they wanted to make sure you didn't get confused, they could have showed his robo-legs.
I still think it was a cheap and useless tie-in to use Maul....
They DID show Maul’s robo-legs!