From what highlights I had seen of him, I was pretty excited by the Tomek pick. Seemed like he had a lot of raw talent and athleticism, almost like a Marc-Andre Fleury type of goaltender. I can see why he might be the type of goalie that coaches wish to develop slowly. That said, it is obviously disheartening that he hasn't yet seen a game, but I don't think it's cause to write him off yet.
We saw with Madsen that goalies can have funny development curves, seemingly not doing anything positive then taking lurches forward, so the fact that he isn't playing doesn't change too much. Ultimately, with mid-round goalie prospects, the long road is all that matters, so I'm not concerned.
At 19 years old, Alex Lyon was only getting his first season of starts in the USHL. Didn't even matriculate to college until 21. That link is good context for understanding his current situation. I'd rather him be getting starts elsewhere, but if he's the starter at UND next year moving forward, he'll have plenty of time to develop his game.
It also may be best for him to have some time before turning pro. The Flyers are so stacked with goalie prospects right now, they're going to need to stagger these arrivals in order for them all to be properly evaluated. Between Stolarz, Lyon, Hart, Sandstrom, Tomek, and even Madsen, the pipeline is going to be flowing for some time.
2017-18:
NHL: Stolarz (backup)
AHL: Lyon (starter)
Juniors: Hart
College: Tomek, Madsen
Sweden: Sandstrom
Then by 2018-19, they should be ready to make a decision on Stolarz and Lyon. And Sandstrom will probably be looking to come to NA by this point, so those two will be getting pushed by Hart and Sandstrom. It's probably better for Tomek to take as long as possible in his pre-pro development.