I would suggest that even without the merger there is a good case to be made for a higher tier. The merger / acquisition of Virgin only helps build the case. Currently there is an abundance of 75k, just this week I was #16 on a waitlist for SEA>ORD for a ticket purchase date 2 weeks prior. Crazy. I can think of plenty of additional benefits for a new 100k tier:
1) higher upgrade priority
2) free meal in coach
3) comp drinks in coach (more than 1)
3) Better boarding priority - now it's inconsistent but mostly "all 75k, and gold, and passengers wearing a sports jersey" (sarcasm intended)
4) more guest upgrade certs
5) higher mileage accrual bonus
6) BR access or passes
7) free onboard wi-fi
I'm sure I could come up with a dozen or so more, but there's plenty of room for improvement for the new Plutonium Level at 100k Alaska metal mile fliers. Right now a 100k AS flyer doesn't have much over a 40k gold.