To add a final conclusion to this thread - these all changed over to Hyatt earlier than excepted on 11th June. Hyatt completed the $2.6bn transaction on that date, clearing all the regulatory and legal hurdles much earlier than expected.

Hilton Playa Del Carmen is now Hyatt Vivid Playa Del Carmen
Hilton La Romana (Adults Only) is now Secrets La Romana (Adults Only Resort)
Hilton La Romana (Family) is now Dreams La Romana (Family Resort)
Hilton Rose Hall is now Dreams Rose Hall

Existing cash bookings have moved to to Hyatt, any status perks will have been lost. Free cancelation or rebooking is available by contacting Hyatt.
Most existing points bookings appear to have been cancelled.