Maybe he's planning on trading Mrazek so the unprotectedness doesn't matter?
Protect Howard, deal Mrazek?
IIRC, Holland did say something about "exploring trades for the players left unprotected".
Maybe he works the phones and sees what he can get for each goalie, and pulls the trigger for the best and/or most cap friendly return? I've got to think that teams like the Jets, Stars, Flames or maybe Flyers would make a pitch for at least Mrazek.
Back on topic....
Here's one big factor that comes with trading or Vegas claiming Mrazek:
After next season, he's due a $4.15M qualifying offer to be retained as an RFA.
If he has another garbage season next year, it probably won't be wise to hand him another offer of that size. At the same time, he'll have a little bit of trade value at the deadline as a rental (see Justin Schultz last year), and that will be it once it passes.
Consider the flip side.... Would Vegas take Mrazek knowing they face the same quandary after the season if they keep him? Looking at that, maybe they still claim him, but do so with the intention of flipping him before the season for a return.
If it were me in Hollands shoes, I'd trade Mrazek for the best return before the expansion draft knowing that if Mrazeks play the last 14 months is the norm, he'll have zero value in a years time.