Honestly, most fans of Picard other than some of us here probably didn't even realize it was a different actor, and may have even forgotten about Maddox from TNG. So I doubt the showrunners have been asked about it.
Now, had it been a recurring role where he was a significant part of the story for the first season or so---maybe then people would start to notice and maybe ask by Brophy didn't return---that's a big maybe. But the role would get more attention then and then people start looking things up and that's when questions come up. But for a 10 minute role, I doubt you'll see significant questions.
For me--I'm a continuity nut. Whenever possible I like to see an original actor for a character come back if the role comes up again--and that goes for any movie or TV series. It's always a nice nod to the previous episode, series, movie, whatever. And I'm curious now why Brophy didn't return. Was he asked? If not, was it considered? It'd be interesting to see what happened, just out of curiosity.
For a 10 minute role--I'm probably not going to sweat it too much other than the curiosity factor. Reading the novel, which Maddox has a larger role in....I do imagine Maddox as portrayed by Brophy.