As of December 11, StR and LC can be made directly through marriott.com (doesn't redirect to SPG). That's good news.
If you had reservations in a St Regis or a Luxury Collections hotel (especially with points), check your reservations today. Both groups were brought over from the SPG platform to Marriott yesterday-the last two to be migrated. Many people on Flyertalk are reporting issues. Such as missing/canceled reservations. Reservations showing as paid that were awards etc.
We have two at StR Maldives that migrated fine but the cancellation changed-for the better.