I think the answer to your question can be argued with varied results.
If age 60 is implemented and a slow expansion occurs then maybe it will delay your upgrade potential.
If age 55 is maintained and the airline could have expanded had they had the trainers etc. then maybe not having age 60 will delay your upgrade potential.
If age 60 is implemented and a quick expansion occurs as a result then maybe it will speed up your upgrade potential.
If age 55 is maintained and the airline does not expand then the status quo is maintained.
Don't get too wrapped up about the implications of age 60 to your command. Its industry standard and a nice thing to have in your back pocket as you hit your early 50's. Also, it's a bit of a trump card at the moment that has a shelf life. The value of it to the AOA is decreasing steadily.
IMHO
