Freshers for post grads

I know that post grad life is completely different to being an under grad but I'm just wondering how you student unions marketed freshers or welcome weeks to you as a post grad? Were your SU's helpful when you were a post grad?

I wouldn't say there is a major distinction. Freshers is still Freshers, despite what degree you are getting. You would still get the same welcome pack, eligibility to attend the same events, and be able to talk to the same people.
As postgrad, you might be able to go into certain areas that undergrads might not be able to e.g. specific rooms for your study, specific bars, etc. As a more mature student, you're expected to be more mature (doesn't stop you from some of the antics that the undergrads are doing, but you are heavily dissuaded from them).
My personal experience of my Student Unions didn't seem to be that involved. Sure they offer events, offer discounts/coupons, and promoted clubs for me to take part in, but I didn't get that much involved with the union - there wasn't a reason to. Having said that, they would help students irrespective of whether they're postgrad or undergrad though.

Thank you! From a marketing POV I'm just trying to get an understanding of what post grads would want to see from their SUs, post grads are a lot more mature than first years so I'm trying to think of a better way to market freshers to them