Marriott is doing something new just for Plat Premier members, it is basically a cert upgrade for any hotel in the marriott family. You book a night using points and you are applied this Plat Premeir cert as your upgrade.
Marriott just started doing that today/tonight. Marriott has been busy answering questions as to what is this? One recommendation is to have Marriott clarify the certs better, via email, because it isn't clear as to what this is. Also, the wording should include transferable to family or friends. Basically, this should be gifted.
For what it's worth I thought (and so did my Spam catcher) this was phishing from some foreign or domestic teenage hacker! Seems to be nowhere on www.marriott.com other than what was contained in that mysterious email. Folks in SLC at the Rewards Desk shed little light on what it meant other than a one night per stay upgrade, much like the United 1K rountrip upgrades in the glory days of commercial aviation--no points required for a nicer time!
So, suggestion is made and seconded: have someone clarify the terms and conditions for the PP10 year-long upgrade for us three percenters who are Platinum Premiers.