This is really quite possible.
First of all, if Howard signs an extension now, he could potentially (depending on the new CBA) stand to make tens of millions more than if he waits to sign with another team.
Second, even if he does wait, the new CBA may have some sort of Franchise Tag, or even if it doesn't, it may even more heavily favor players staying with their current teams.
Third, even if that doesn't happen, the cap may be lowered so much that teams that thought they were going to have money (like us) may not have as much as we thought.
In either case, Howard could be turning down tens of millions of dollars by walking away from the Magic. So I wouldn't be surprised to see him stay in Orlando.