My guess is they may require more nights if they change the criteria for lifetime status. Rollover nights have made it easier for people to accumulate nights. The 12 year requirement seems unlikely to change, and it would look stupid if they increase the point requirements after lowering them. I realize Marriott has done stupid things before, but I think this possibility is low.
Frankly, I would rather see them change nothing and make lifetime status more public. I am waiting to hit the 12 year mark, and I'll be screwed if they raise nights significantly. I have enough points, unless they decide lifetime platinum needs 5 million.