Given that this movie is a reboot of a franchise, I think it's not unreasonable to think that if the movie succeeds they'll keep doing movies.
The whole trilogy thing has long since overstayed its welcome, and I don't care to see it here at all.
If this movie does well enough, bring back Edwards and the creative team behind the success and get them to work on another one. If that one does well. Do it again. If it ain't broke, don't "fix" it. Legendary, if they pull this off, could ride the train all the way until it finally flops which could be anywhere from 1-however many they manage to squeeze in before it runs into a wall.
But no trilogy. I'm sick to death of trilogies. They've long overstayed their welcome and I personally will feel quite betrayed if Legendary does well this time and says "Trilogy."