Reading the T&C's it does read as if you will have to carry on earning AU status until you do hit the 7500 TP's flying VS threshold.
From the T&C's and my bolding as it mentions a minimum of 10 consecutive years.
2.24. Lifetime Gold Membership
2.24.1 To qualify for Lifetime Gold status, a member must have earned a minimum of 10 consecutive calendar years at Gold status.
2.24.2 The Gold member must have earned a minimum of 7,500 tier points during their consecutive years at Gold status on VAA operated and marketed flights.
2.24.3 Transactions that are excluded from the 7,500 tier point criteria include codeshare flights, manually added tier points including gestures given to members, and bonus tier point offers.
2.24.4 If a member has been given a complimentary Gold status, this is excluded from the criteria to reach Lifetime Gold status.
Flying Club will be able to tell you the number of TP's you have earned on just VS flights.