Hi @PhilipDAth Thanks for you reply.
Meanwhile i got reply from Meraki support that we just need to move vMX to another account and then need to reauthenticate vMX from their. But as we know Meraki support is totally unreliable.
So, I am planning to still follow Meraki suggestion and if it doesnt work then deleting the network (we are planning on standby Meraki first) as it must free the license as well and then building secondary from scratch in new vMX. On basis of this, planning of primary vMX migration by failing over prod traffic to secondary vMX.
Let me know your view on this.