Yeah, I think that's a fair analysis. He has been a tough guy to figure out. As a rookie in 2017 he came on pretty fast and after their bye week was playing a lot and did well for a rookie. 2018 came and- apart from his fantastic KC game- he just didn't do a lot. 2019 he flashes here or there but nothing consistent. Though he did have more sacks (4.5) in 2019 vs 2018 (3.0) in 20% fewer snaps (plus 10 QB hits vs. 6).
Maybe, as you said, his role will be more of a situational run defender and special teams leader. Mike Jones, George Andrews, etc. were never pass rush guys either and they were productive assets. Who knows, maybe Staley can help him develop those counter pass rush moves he's never seemed to have. Ebukam has always been a high motor guy.