What baggage does he have? Sincere question, I don't know about this.
He was suspended twice in junior for violating the league's harassment and abuse/diversity policy. Once for an issue with comments made to a teammate behind closed doors and once for something that happened mid-game. He was also suspended in junior for abusing an official. In his first game back from suspension, he was ejected for once again abusing an official.
He was drafted 19th overall in 2014 by the Lightning and made the AHL in his D+2 season. He had a productive season (43 points in 67 games) but was scratched a few times (the team never said why). In the summer following this season (2016), the Lightning traded him to Arizona for the 37th overall pick.
In the 2016/17 season he split time between the AHL and NHL. During his first NHL stint, he was suspended for 3 games for abusing a ref. That summer he was traded to the Rangers in the Raanta/Stepan trade.
He split time between the NHL and AHL in 2017/18 and then made the NHL full time in 2018/19. He was healthy scratched about 20 times in 2018/19 at least in part over maturity issues (according to the coach). He was awesome in 2019/20, got a 2 year deal worth $4.8M a year in the summer of 2020. Then there were some unknown off-ice stuff that caused him to be healthy scratched early in the season. The GM told him that he was on his last strike. 5 games later, he got in a fight with Georgiev and was waived just 3 weeks into the first season of his contract extension. He cleared and rather than sending him to the AHL the Rangers just told him to go home and collect a paycheck away from their prospects. He was bought out that summer.
He went to Carolina on a cheap 1 year deal in 2021/22 and had a good year. They traded his rights to Philly who signed him to a 2 year deal and he had another good year in 2022/23. It was rumored that Philly was going to trade him back to Carolina, but they instead chose to buy out the last year of his deal.
The baggage is a pretty long history of abusing officials and generally being enough of an asshole to merit multiple suspensions, healthy scratches, two teams electing to pay him not to play (despite on-ice production) and the team who drafted him trading him for a noticeably worse pick than they used to draft him after a good rookie AHL season. Or politics. Probably just politics.