I do not think publish dates are announced until GA
Your customer will have to wait until there's a 6.7 target release that supports upgrade from 6.5 U3. We do not publish dates in advance as there's a lot of factors that can change the actual GA date.
Thank you very much, this linkg documentaion read it.
Today try it 6.7 U2c versiyon, 1 PSC machine migrated 6.7 U2c no error and no problem. Tomorrow try to other psc or vcenter server migrated. The last status pubished this post.
Today try it second 6.5 U3 PSC, and 6.5 U3 vCenter VCSA migration do it.
Try to vCenter 6.7 U2c Embeded PSC converged no problem compose to embeden psc do it.
Try to two PSC Server decomposed do problem decomposed psc server.
VCenter 6.5 U3 migration supoorted 6.7 U2c version on my customer.
Thank you very much.