For every SAFe implementation it is imperative that we first make sure all leaders are trained and embrace the lean-agile mindset, agile values and principles.
With the proper mind-set in place, Normalization of story points is a tactic that creates ease in forecasting, budgeting and setting milestones on large initiatives, capabilities and features that span across many teams.
What normalization means is that every team uses an exemplar story to baseline sizing that uses approximately the same duration. This common exemplar duration is team specific for each teams particular context.
When doing this, you will avoid the situation of having one team of 7 people that has a 2 week iteration velocity of 120 points, and another 7 person team that has a 20 point 2 week iteration velocity. If these two teams are working on a common deliverable or feature set, it becomes problematic with forecasting on that common batch of work. Add more teams to the mix without normalizing, and minimally you could say forecasting would not be straight forward and transparent.