You can already do this with merit tokens. Once you have a character into either Elite or Ultimate Forgotten Gods content that character can buy them and put them in the transfer stash for your other characters to use.
If you have the Crucible add on you can make a new character, choose Crucible instead of the Main Campaign and go to the smuggler in there to get the token and use it, then return to the main menu, switch back to Main Campaign and then choose either Elite or Ultimate depending on which one you want to skip up to start at L1.
Bear in mind that skipping will mean the usual difficulty penalties will be applied to your resistances: 25% to the top row if you skip to Elite and a 50% hit to the top row plus as 25% hit to the bottom row if you skip to Ultimate.
Another option if you want to try it is to play the game classless, i.e. don’t choose any masteries and only have skills, etc, from items/devotions. There is even a reward in the game for doing so.