Social media wasn't as big of a factor as it was during the Prequels and Lucas had far more control of everything going on. Now studios are paying for social media tracking and there are independent tracking services gauging not just the volume but the tone of social media comments.
How much hype and buzz really matters is up for debate. Six months out, the buzz for Jumanji was incredibly negative and now it's expecting a $15 Million plus weekend in it's 6th week while the TLJ will struggle to get $4 Million in its 7th week (20% below Rogue One). Jumanji is still in 3,553 theaters while TLJ is only in 1,745. Other studios must be kicking themselves for giving TLJ so much space and Episode IX won't be so lucky. Other studios are going to want have the next Jumanji and Episode IX will face far more competition.
The message from Disney execs to JJ is likely is to make Episode IX appeal more to all 4 quadrants. Jumanji is cranking right now because its much more of a family movie than TLJ and people are seeing it multiple times because it's so much fun.