The Terengganu Royal Philatelic Presentation issue was prepared for an event in 2013. Technically it was “unissued” until yesterday evening (Friday, 05 December 2014). This item was hotly chased today by dealers and by casual visitors as it is really attractive!
The miniature sheets comes in a regular perforated Miniature Sheet as well as in Imperforate Miniature Sheet.
Thus the official date of issue is 05 December 2014.
There was no publicity nor announcement at the exhibition. It caught many by surprise.
In the absence of an official envelope, the WYSE envelope was used.
I am sure with time, someone with spare envelopes from the past or (shudder thinking about it) someone might tear out the old stamps to stick this since the issue is not “hot” anymore!
Updated 08 December 2014:
Here are some common FAQs:
1. The MS will be made available on PostMe. This will help you to decide whether to buy online or wait.
2. SODA – Order Forms will be sent to SODA for the mint MS.
3. MS FDC – not available.
4. Quantity issued: No information yet.
sky52200
myfdc 
Hi, thanks for the information. I was caught by surprise when they are offered on ebay. I am only starting to build a small Trengganu collection. Seen many, envied many including collection of Sir Gawaine Baillie’s Trengganu collection.
They will make a good entry into my Trengganu hoard. HEHE
Best wishes for your collection!
sky52200