A surprise find in The Philippines, as it has shown up without any leaks or teases - a 10 Year Anniversary Transformers Prime pack.

Unfortunately, more than a day later, we still have no idea what is inside the brown cardboard box, which itself has no window or toy image on the box.
We have the following details from the box...

Size class - Deluxe
Contents - 1 figure.
Name - War Breakdown Vehicon.
Product number - E9687

The Voyager sized Breakdown toy was never released by Hasbro, which was really surprising at the time, and frustrating for fans... as it was released by TakaraTomy, and called "War Breakdown". (the mould was never released as just "Breakdown"... and just as frustratingly, the two redecos for the same toyline were also only released in Japan)
The first time that this mould was actually released by Hasbro, it was a limited edition BotCon convention toy (as Megatron), so if this is indeed that same mould, it once again looks to be a limited release of this mould to Hasbro markets.

Since the box says Deluxe class, it is more likely to be a redeco/new head of a recent toy, as the TFPrime Breakdown toy is too big to pass as a Deluxe toy.

Hopefully we get to see the contents really soon (if not already somewhere), and that it is something interesting to be worth being an Anniversary toy.