OK, the intent was indeed actually to only show the icon (like elsewhere). So that makes the current issue no more a bug, but an improvement request.
For me, it's two fold (from a "product" management perspective): either we just close this bug as wontfix because we want to keep the complexity low, or we add a new column variant named for example 'last build trigger - long version' and reintroduce a column with the old behaviour.
If we were on a big product, I'd say the first solution may be better. In our case, I suppose the second case is feasible since the codebase is still pretty small. Though we sure want to reuse as much code as possible if we introduce that second column being a 'long' variant of the current one.