Blue
Ravenous Bugblatter Beast of Traal
A DM riffing off an established background is good. Your background should be providing connections to the world and hooks for the DM.
Where "riffing off" changes to "adding something major enough that it changes things" is a blurry line. To use as apples-to-apples comparison as I can, my rogue player would have no problems with someone coming after him for a bounty on his head - a bit her set up. But he would (rightfully) have a problem if someone came after him for squealing to the Bracers (the local guards) and getting him throw away because that's not something his character would do.
Some players offer me broad strokes and let me fill in as needed. Others are more particular.
My table has a lot of trust around this, which also goes the other ways in that I often ask my players to flesh out details for places or organizations they would know. Or pull out a "hey, do I have any contacts in this city through my old guild" just like your player did and I run with it.
Where "riffing off" changes to "adding something major enough that it changes things" is a blurry line. To use as apples-to-apples comparison as I can, my rogue player would have no problems with someone coming after him for a bounty on his head - a bit her set up. But he would (rightfully) have a problem if someone came after him for squealing to the Bracers (the local guards) and getting him throw away because that's not something his character would do.
Some players offer me broad strokes and let me fill in as needed. Others are more particular.
My table has a lot of trust around this, which also goes the other ways in that I often ask my players to flesh out details for places or organizations they would know. Or pull out a "hey, do I have any contacts in this city through my old guild" just like your player did and I run with it.