I have a lot more miles to go for Life Time PLT, but I am thinking of same thing because of this announced change of AAdvantage program.
If I were in your situation, 45,000 miles to go for Life Time PLT, then I will do it. But it all depends on how many leisure travel you will do and what will be miles earned from those flights, quick LGA-DCA shuttle flights vs. round trips on NRT.