There is no reason for Hextall to rush.
Most prospects, outside of a few 1st rd picks, don't arrive until they're 22-23 (college/juniors, 1-2 AHL seasons).
So to build a critical mass of young talent, starting with one of the worst farm systems in hockey, takes about 5 years.
In year 4 we're seeing the first wave, year 5 the next wave.
There are two kinds of deals:
1) "take out the trash," Hextall has been making these for 3 years, if he can move MacDonald, Lehtera, Filppula, Read, etc. he will, but since he's not cap constrained he's not going to sacrifice real assets (see Hartnell deal).
2) "chess moves" - this is where you sacrifice real assets to obtain other assets that are a better LONG-TERM fit.
Flyers are not in win now mode where they try to obtain the one player that might put them over the top, and hopefully, with the steady supply of talent, they never will be.
When Hextall makes a serious trade, it's likely to be young talent for young talent, in a year or two with excess defensemen he might put a package together for a young prospect who is cost controlled, but not a "name" who's close to free agency and will bust the salary cap.
Most likely, deals this year will be "trash" deals, where he moves a couple veterans for draft picks and shifting salaries around, maybe add a short-term patch.
The big deals are probably a year or two away after they assess their young talent and decide who are the "keepers" and who is trade bait.
The wild cards are Simmonds and Voracek, Simmonds because of impending contract/UFA concerns, Voracek because of fit (can he play in this scheme at a high level?).