This post refers to the Original Version of Rocksmith. NOT Rocksmith 2014.
According to a Facebook post from an actual Ubisoft Rocksmith employee/developer (Nao Higo), the PC version of Rocksmith will come with all DLC songs released to date.
Unfortunately, this post was not well-written and has been taken out of context.
IT'S NOT TRUE. You won't get 124 songs with the PC version. Just the same original 51 songs that have come with Rocksmith since last October.
Apparently the PC version will merely let you buy all currently released DLC. In other words, all the DLC will be in the online store in the game. Duh.
Evidently there was some concern in the Europe market that players in Europe wouldn't have access to the full inventory of DLC in the in-game store. Not sure why that would have been the case, but whatever.
So, this sort of wonky FB post is good news for those people in Europe who were worried about this, but it's pretty much meaningless for players in the U.S. Sorry, America. False alarm.