GM please system global of this MERGE 2 weeks in advance.
Also, email notification of this MERGE.
Then, it's all fair notices and ample days to be prepare.
Players who has contact with your old friends, let them know of this MERGE so they could prepare all their accounts for the MERGE without any lost of their stuffs.
Please do not procrastinate on this preparation, because if you have to RT on some accounts, GM won't be so bombarded with RT at last minutes.