I'm guessing we'll still be pretty bad. Jumping to 20th best in the league would a huge (and, for me, highly encouraging) jump.
I'm saying this in large part because I think a lot of great defense (except for the true defensive freaks) depends on both individual experience and collective experience together. We'll still be at a huge deficit in both. Last year we had Dunn and THT (who was as least competent) playing real minutes at times in the backcourt, but we still had basically no chance defensively, aside from that one midseason run where everything seemed to coalesce and we were playing mostly bad/diminished teams.
If we make a defensive jump with this group, I'm expecting it to be 2025-6.
Individually, I think Hendricks is still a bit too raw to really produce great defense consistently, though hopefully by the end of the year, that's beginning to change.