I logged on to search for this topic. I suspect it has been covered. But I didn't find it.

I am a co platinum traveler. I have some membership rewards w Amex -- about to be de linked from co.

I went to Amex to transfer those points today, and I got a warning that with united, miles will expire. And that even after sept 30, I can still use points from Amex to book on co and united using "pay w points".

Do I transfer or don't I?