As America inches state by state into regulated online gambling, rumors of a US Network have started to circulate, with PartyPoker at the center. Players at BetMGM and Borgata Poker in New Jersey recently received emails about a chance to win an entry into a PartyPoker US Network $250K Freeroll. The event is slated for January 26. The use of the term US Network appears to be new branding for PartyPoker. While the term US Online Poker Network could mean a variety of things, best guesses say that PartyPoker could be planning to go live in Nevada and then merge…