It won't be outlawed as long as public will be against it. It will be a political suicide for opponents of encryption. But only if public will be against it. Time will tell.
Did the Congress authorize all that uncostitutional surveillance for example? I thought it was a secret court interpreting the law in secret on behalf of the executive power. So "passing laws" in such context is not a far fetched claim.
That wouldn't require Obama to wait until just before leaving office. Anything done in secret has already been implemented. What the FBI is asking for could likely be done by the NSA already. The Feds want a publicly known law or ruling they can use as a club over private companies, so they don't have to break any more encryption; they want it all handed to them. And they're too shortsighted and pigheaded to see/admit the folly of what they're asking.
Further the agenda of his political donors and pave the way for the successor. Or make it difficult for an adversarial successor to pass opposite laws.
