It'll depend on recruiting and player development.
Certainly, both the O-line and D-line should be improved in 2020. I think our secondary will be rock solid, as well. We'll probably get JG back for a Senior campaign, and our backup QB options should be better, too.
The question marks are mostly in areas where we lose a lot of key players. We lose 2 and maybe 3 of our top 3 WRs (Jennings, Callaway, possibly Palmer). We lose DWA at TE. We lose Bituli and Darrell Taylor at LB. Also a decent chance we lose Ty Chandler at RB. If we can successfully replace most of those guys, then 2020 could be good.
The good news is that it's typically easier to replace most of those positions (RB + WR especially) in a short period of time, whereas the OL and DL takes years of development.