To be fair, an alternate Universe DLC, if handled correctly, could actually work. Of course the example given is a bad example, as since the Player Character going to an alternate universe is silly, and the difference made changes absolutely nothing.
If they, for example made an alternate universe where you wake up from Cyrogenic Chamber to find out that that for example, The US was ruled by the Enclave who killed The Chosen One before he blew them up, that would kinda be cool, however any Alternate Universe that is either pointless, or interferes with the current Cannon Universe is a no no.