I agree with @danmaruschak. Aside from connecting to TRX rewards, JS has seemed pretty-much like a non-factor for the last 20 months, so I don't expect much to change in the short term.

Longer term, his departure could be good, could be bad, or could be neutral. I don't really have enough knowledge to have a strong opinion, but if I were forced to guess, I'd guess "neutral to slightly positive". If developers were paralyzed waiting to see what the Tron Foundation would do, this might spur them to action.

Uncertainty in the crypto markets, who would believe it? ;-)