I've never heard of TO even trying to resign him, I think he was moved because he simply wasn't good enough.
Brown is an interesting case I think, he's small and slow yet he still managed to have a decent AHL rookie year, surprising.
He scored reasonably well, which is good, but what's more telling is his shots for which to me is an indication of his offensive upside instead of just goals which could be puck luck. Leivo had 140 shots in 59 games last year, his rookie year or about 2 1/3 shots per game, I thought this was pretty impressive but this year he regressed in goals for but not shots for so I think there is still some promise in him, hopefully he simply had the sophomore blahs. Brown's shots for weren't as good, 131 in 76 games played, less that 2 per game but his point total percentage wise equaled Leivo's.
It's hard to get excited about either of these players because far better offensive contributers in their rookie years have never amounted to much in the NHL, if anything. In the Hockey News Brown is ranked as TO's 5h best prospect which doesn't mean he's a good prospect just TO's 5th best.
I think it'll be a stretch to expect Brown to become an NHL player because of his size, skating issues, small slow players rarely if ever carve out an NHL career, Brown so far has exceeded my expectations so hopefully where there's life there's hope.