I’ve been taking “multiple weeks” to mean 2-4. Blizzard will want xfers open ASAP. That’s ALOT of money they are losing by keeping that service closed. No way it’s longer than 4 weeks. And my suggestion of 2 was partially hope / wishful thinking for a may 18th prepatch goal still.
The words “After this closure” implies that the service will come up before the snapshot. Or it’d be “DURING” the closure, not after. That said, blizzard does not have the best track record with phrasing things in a clear / proper manner. So they very well could have meant “after the closure starts” or some such nonsense.