Update: Received a "Welcome New Owner" email from Vistana yesterday, June 6, 10 weeks from March 29 closing date. Logged into my existing account, but nothing new was showing up. Closing agent told me to wait 48 hours. Today (24 hours later), one of the two reserved weeks showed up in my account (yay), plus the week now shows up in my Account Balances list. Maybe the second reserved week will show up tomorrow.
Of course, the timestamp for the first reserved week is horrible since they cancelled the 12-month out booking and rebooked it, so that's a bummer, but not unexpected.