I mentioned this already probably back on like Page 12 or something, but that's not really what the G-League is anymore.
G-League locations now (and NBA affiliate):
- Wizards - DC
- Cavs - Cleveland
- Hawks - College Park (AKA Atlanta)
- 76ers - Wilmington (40 minutes to Philly)
- Pacers - Indianapolis (still named Fort Wayne Mad Ants but they play in downtown Indianapolis)
- Nuggets - Grand Rapids, MI
- Hornets - Greensboro
- Brooklyn Nets - Long Island
- Celtics - Portland, Maine
- Pistons - Detroit
- Magic - Kissimmee (30 minutes to Orlando)
- Raptors - Mississauga (40 minutes to Toronto)
- Knicks - Bridgeport, CT
- Bulls - Hoffman Estates, IL (technically a suburb of Chicago but its close to an hour to get to the River North area)
- Bucks - Oshkosh (over an hour to Milwaukee)
- Spurs - Cedar Park (almost 2 hours to San Antonio)
- Pelicans - Birmingham, AL
- T'Wolves - Des Moines, IA
- Grizzlies - Southaven, MS (15 minutes to Memphis)
- Thunder - OKC
- Clippers - Ontario, CA
- Rockets - Edinburg, TX
- Jazz - Salt Lake suburb
- Warriors - Santa Cruz
- Heat - Sioux Falls, SD
- Lakers - El Segundo (maybe my favorite thing in the G-League...they're arena holds 750 people)
- Kings - Stockton, CA
- Mavericks - Frisco, TX (outside of Dallas)
There aren't many teams left that aren't located either right by their NBA affiliate or in a legit city of their own.
Those four cities you mentioned are already bigger than Syracuse btw (you obviously have a point about the number of people that attend G-League games, but I don't think players care all that much tbh; they're more focused on getting to the NBA anyways).