There could be open online discussions, which can be streamed live and/or recorded. 
It could improve cross campus student engagement. More "food for thought". It would be beneficial for the students participating. There could be guest speakers or just students discussing specified in advance topics. They can be voted or set by someone. Pretty much the opportunities are endless. However I am not aware how the Union and University work with one another and what is in whose jurisdiction. As how I see different variations, most of it would be beneficial, to the parties involved. University can directly benefit, in at least two ways. It could be easily be used as sort of a I ncubator and a sales funnel. 
If rules are established and it's more challenging this can be turned into a practical kick starter. Meaning that students which participate and have meaningful discussions, could be incentivised by the Uni or SU. There are many options which can be developed. I would be happy to discuss and clarify further.