I doubt they will be any worse next year but I don't think they'll be significantly better either. They've probably bottomed out IMO because the 2019 team should at least be a bit more entertaining....
The 2019 roster will be eminently more watchable with young players like Jansen and Vlad and others in the fold. These guys, along with expected bounce backs from some of the core players like Stroman or Sanchez, will also probably mean that the Jays have at least a couple of above average / star level players even if the overall team doesn't win much. There will also be some interesting to watch "sink or swim" young players like Biggio, McKinney, Alford, SRF, Drury, etc. (guys who could be good but could also, reasonably, bust entirely). Decent chance the defense is horrendous again but it could also turn around if athletic guys like Alford and Bo can get a foothold.