Its relative.
A big halo announcement could of been anything.
A big announcement in the world of halo toys has a lot less scope for wow factor, as someone who follows halo toys it was a big announcement. We got confirmation that a new line of Halo stuff was being developed by a completely new company and we even got pictures about what to expect, the toy world is shrouded in secrecy this was most certainly big news.
Seeing a new vehicle in toy form is pretty much an unrealistic expectation, the only thing we have ever got that would be similar is the redesign of the scarab from halo 2 to 3 being shown first via toys but for them to annouce a completely new vehicle has huge repercussions.
A new vehicle would more likely that not have to be something other than UNSC. Since the UNSC vehicles are already known.
Now lets for arguments sake say the new vehicle was forerunner chopper. That dosnt only confirm a new vehicles it imply's we would get forerunner tech which imply's forerunner enemies which gives us some idea about the Reclaimer trilogy story arc something which is obviously very tight underwraps.