Rather than the anime alone, it also depends on if it did well for merch and manga / LN sales. The other thing to consider is that the team working it were those who usually work on DanMachi (you could tell from how it was animated, the colours and style of animation as well as the staff credits) and obviously that is a huge ongoing project so there’s going to be less time for going back to something like Executioner. I believe the original light novels are finished, so there’s nothing to ‘promote’ there in that sense now.
A shame since I really enjoyed it and would have liked to see more anime for it (tho not at the expense of DanMachi, admittedly…)