Yea nah, that doesn't make any changes to the existing be a pro career, no new jerseys or centre ice, the game doesn't stop you from playing just because there is no roster selected, I can even start a new be a pro career without a roster selected at all, once in the nhl it appears to be using the games release roster, I've tried this a dozen times now and it's the same regardless of which roster I've attempted to use, my own custom, community custom, ea, it doesn't make any difference, if a custom roster is selected the name of that roster will change when starting a new career to just a random date that predates the nhl itself, it's as if the roster files are being corrupted when put in to use