Yes, but that six weeks includes quals on more than one equipment type, and all the aspects of the service delivery. If you remove service delivery, and bring it down to just safety functions on a single aircraft type, the timeframe can shrink, presumably to less than two weeks. There's plenty of precedent for this being approved by the FAA in the past, including 1993, but more recently, with NWA.
How long would it take to train replacement workers?
In 1993 it took 11 days
That was pre 9/11. Now they need fingerprints and background checks
*If they found people to train replacement workers (remember the trainers are FAs on trip removal), AND they ran the learning center for 24 hours a day 7 days a week, it would take them 1 year to train 10,000 flight attendants on 1 aircraft type.