There's a saying in the bodybuilding world, "Side delts can never be too big", so pre-exhausting them to make them the focus of a shoulder session is pretty common, for sure.
This should trump most replies from people. Stick with your plan for 4 or 6 weeks and see where you end up. Make note of pressing strength, bodyweight, and how your shirts are fitting across the shoulders/chest/upper back.
What does the rest of your weekly split look like?
Two shoulder sessions per week is pretty much a shoulder specialization plan since they're a relatively-small muscle group. That's not necessarily a bad thing if that's your current goal. Just saying.