I have also had the "welcome to BAEC" email and posting as Blue on the "new" account - though I'm Gold on my normal one
my Avios account balance was something pathetic like 600 Avios - I can't remember why I ever had it - all my Avios collection is from flights and my BA Amex, which posts direct to the "real" BAEC Gold account
Long story short - do I actually need to do anything at all here? Assume I don't care about the tiny Avios balance left behind. Can I just totally ignore this?