Welcome back, and this is the correct forum to ask
That cooldown was removed a little over 6 months ago, so you're free to change clans at any time with no wait period in between. This cooldown is now in effect for Citadel skilling.
For example, if you capped at the Citadel 3 days ago, you could not cap for another 4 days, regardless of whether you change clans or not.
~ Sicariu
Leader of