If the expansion draft is held in 2020, basically every currently signed prospect or player save Valimaki, Dube and Phillips will be exposed. The rules are two years of pro experience or less to be automatically protected and all three of those aforementioned guys are only going pro this year. Which means they'll only have the two years of experience and thus, be exempt.
To start with, two years is a long time in the NHL and it's entirely possible there will be significant changes that make all of this pretty pointless. But for fun, and working only with those already in the system, you can create a rough framework.
If they choose to go 7-3-1, it likely works out to five players as relatively safe locks in Gaudreau, Monahan, Tkachuk, Lindholm, and Backlund while the remaining two spots are contested between Jankowski, Bennett, Neal, Czarnik, and Mangiapane. Also possibly Ryan works himself into that conversation. Frolik will be a UFA.
The expansion draft or the lockout (compliance buyouts) might be the best opportunity to get rid of Neal's contract if it goes south.
Secondly, with regards to the defence, Brodie, Hamonic and Stone will be UFA's that summer. Giordano and Hanifin will still be under contract while Andersson and Kylington will be RFA's. Kulak's a wildcard. A lot depends on Giordano; if he's declined you go with Brodie. If not, things get dicey. So it could be Giordano/Brodie, Hanifin and one of Andersson or Kylington for the list. But there's also the option of trying to re-sign Brodie and maybe Hamonic after the draft and protecting someone else.
On the other hand, going 4-4-1 makes sense if one and only one more forward joins the big three of Monahan, Gaudreau and Tkachuk making it a big four. And at the same time, both Kylington and Andersson solidify themselves as top four or better defencemen. Hanifin's presumably a lock and you either protect Giordano or if he's declined significantly, a re-signed Brodie. So then, at that point, it's basically a choice between losing one Backlund/Lindholm/Jankowski/Bennett/Neal/Czarnik/Mangiapane or Giordano or a soon to be UFA Hamonic/Brodie. Most likely, you lose one of the good young/entering their prime forwards.
As for goalies, if the Flames even have one good goalie to protect, let alone two to worry over, I think everyone is happy. If things go according to plan, it'll probably be Parsons protected.
Lastly, there might be a lockout that season so expansion could be pushed to 2021 in which case, those three players mentioned all the way at the beginning (Phillips, Dube and Valimaki) would also be available to be taken while presumably Brodie would be re-signed. Maybe Hamonic too. Basically, it'd be a lot more complicated and ugly of a situation.
For strategy, the only real goal is avoid repeating the mistakes the Wild and Panthers made. Best and perhaps least expensive strategy would be to follow the Jets, who traded down in the first round to protect their players. But the Jets were only protecting Dano and Enstrom; the Flames will presumably be protecting much better talent. Another choice to be to copy the Ducks are trade an emerging, protected talent in exchange for a cap dump being taken (Ducks traded Theodore so the Knights would take Stoner). For example, trade a Valimaki or Dube or someone else promising so the Seattle Starbucks take Neal/bad contract as well.
Or just cash your 32M cheque, don't overthink things and just let them take the eighth best forward or the fourth best defenceman or second best goaltender. Either way though, it's pretty much a guarantee the Flames are going to lose a much better player this time around.
